diff --git a/Data/Scripts/003_Game processing/002_Scene_Map.rb b/Data/Scripts/003_Game processing/002_Scene_Map.rb
index ceafdadef..d09d9ac90 100644
--- a/Data/Scripts/003_Game processing/002_Scene_Map.rb	
+++ b/Data/Scripts/003_Game processing/002_Scene_Map.rb	
@@ -156,7 +156,7 @@ class Scene_Map
     @spritesetGlobal.update
     pbDayNightTint(@map_renderer)
     @map_renderer.update
-    Events.onMapUpdate.trigger(self)
+    EventHandlers.trigger(:on_frame_update)
   end
 
   def update
@@ -214,7 +214,7 @@ class Scene_Map
       elsif $game_temp.interact_calling
         $game_temp.interact_calling = false
         $game_player.straighten
-        Events.onAction.trigger(self)
+        EventHandlers.trigger(:on_player_interact)
       end
     end
   end
diff --git a/Data/Scripts/003_Game processing/005_Event_Handlers.rb b/Data/Scripts/003_Game processing/005_Event_Handlers.rb
index d2efe92d3..03d000989 100644
--- a/Data/Scripts/003_Game processing/005_Event_Handlers.rb	
+++ b/Data/Scripts/003_Game processing/005_Event_Handlers.rb	
@@ -60,7 +60,38 @@ class Event
 end
 
 #===============================================================================
-#
+# Same as class Event, but each registered proc has a name (a symbol) so it can
+# be referenced individually.
+#===============================================================================
+class NamedEvent
+  def initialize
+    @callbacks = {}
+  end
+
+  # Adds an event handler procedure from the event.
+  def add(key, proc)
+    @callbacks[key] = proc if !@callbacks.has_key?(key)
+  end
+
+  # Removes an event handler procedure from the event.
+  def remove(key)
+    @callbacks.delete(key)
+  end
+
+  # Clears the event of event handlers.
+  def clear
+    @callbacks.clear
+  end
+
+  # Triggers the event and calls all its event handlers. Normally called only
+  # by the code where the event occurred.
+  def trigger(*args)
+    @callbacks.each_value { |callback| callback.call(*args) }
+  end
+end
+
+#===============================================================================
+# Unused.
 #===============================================================================
 class HandlerHash
   def initialize(mod)
@@ -144,7 +175,8 @@ end
 
 #===============================================================================
 # A stripped-down version of class HandlerHash which only deals with symbols and
-# doesn't care about whether those symbols actually relate to a defined thing.
+# doesn't care about whether those symbols are defined as constants in a class
+# or module.
 #===============================================================================
 class HandlerHash2
   def initialize
diff --git a/Data/Scripts/003_Game processing/006_Event_HandlerCollections.rb b/Data/Scripts/003_Game processing/006_Event_HandlerCollections.rb
new file mode 100644
index 000000000..eeb0ccc92
--- /dev/null
+++ b/Data/Scripts/003_Game processing/006_Event_HandlerCollections.rb	
@@ -0,0 +1,65 @@
+#===============================================================================
+# This module stores events that can happen during the game. A procedure can
+# subscribe to an event by adding itself to the event. It will then be called
+# whenever the event occurs. Existing events are:
+#-------------------------------------------------------------------------------
+#   :on_game_map_setup - When a Game_Map is set up. Typically changes map data.
+#   :on_new_spriteset_map - When a Spriteset_Map is created. Adds more things to
+#     show in the overworld.
+#   :on_frame_update - Once per frame. Various frame/time counters.
+#   :on_leave_map - When leaving a map. End weather/expired effects.
+#   :on_enter_map - Upon entering a new map. Set up new effects, end expired
+#     effects.
+#   :on_map_or_spriteset_change - Upon entering a new map or when spriteset was
+#     made. Show things on-screen.
+#-------------------------------------------------------------------------------
+#   :on_player_change_direction - When the player turns in a different direction.
+#   :on_leave_tile - When any event or the player starts to move from a tile.
+#   :on_step_taken - When any event or the player finishes a step.
+#   :on_player_step_taken - When the player finishes a step/ends surfing, except
+#     as part of a move route. Step-based counters.
+#   :on_player_step_taken_can_transfer - When the player finishes a step/ends
+#     surfing, except as part of a move route. Step-based effects that can
+#     transfer the player elsewhere.
+#   :on_player_interact - When the player presses the Use button in the
+#     overworld.
+#-------------------------------------------------------------------------------
+#   :on_trainer_load - When an NPCTrainer is generated (to battle against or as
+#     a registered partner). Various modifications to that trainer and their
+#     Pokémon.
+#   :on_wild_species_chosen - When a species/level have been chosen for a wild
+#     encounter. Changes the species/level (e.g. roamer, Poké Radar chain).
+#   :on_wild_pokemon_created - When a Pokemon object has been created for a wild
+#     encounter. Various modifications to that Pokémon.
+#   :on_calling_wild_battle - When a wild battle is called. Prevents that wild
+#     battle and instead starts a different kind of battle (e.g. Safari Zone).
+#   :on_start_battle - Just before a battle starts. Memorize/reset information
+#     about party Pokémon, which is used after battle for evolution checks.
+#   :on_end_battle - Just after a battle ends. Evolution checks, Pickup/Honey
+#     Gather, blacking out.
+#   :on_wild_battle_end - After a wild battle. Updates Poké Radar chain info.
+#===============================================================================
+module EventHandlers
+  @@events = {}
+
+  # Add a named callback for the given event.
+  def self.add(event, key, proc)
+    @@events[event] = NamedEvent.new if !@@events.has_key?(event)
+    @@events[event].add(key, proc)
+  end
+
+  # Remove a named callback from the given event.
+  def self.remove(event, key)
+    @@events[event]&.remove(key)
+  end
+
+  # Clear all callbacks for the given event.
+  def self.clear(key)
+    @@events[key]&.clear
+  end
+
+  # Trigger all callbacks from an Event if it has been defined.
+  def self.trigger(event, *args)
+    return @@events[event]&.trigger(*args)
+  end
+end
diff --git a/Data/Scripts/003_Game processing/006_Event_OverworldEvents.rb b/Data/Scripts/003_Game processing/006_Event_OverworldEvents.rb
deleted file mode 100644
index 6d91bc9de..000000000
--- a/Data/Scripts/003_Game processing/006_Event_OverworldEvents.rb	
+++ /dev/null
@@ -1,172 +0,0 @@
-#===============================================================================
-# This module stores events that can happen during the game. A procedure can
-# subscribe to an event by adding itself to the event. It will then be called
-# whenever the event occurs.
-#===============================================================================
-module Events
-  @@OnMapCreate                 = Event.new
-  @@OnMapUpdate                 = Event.new
-  @@OnMapChange                 = Event.new
-  @@OnMapChanging               = Event.new
-  @@OnMapSceneChange            = Event.new
-  @@OnSpritesetCreate           = Event.new
-  @@OnAction                    = Event.new
-  @@OnStepTaken                 = Event.new
-  @@OnLeaveTile                 = Event.new
-  @@OnStepTakenFieldMovement    = Event.new
-  @@OnStepTakenTransferPossible = Event.new
-  @@OnStartBattle               = Event.new
-  @@OnEndBattle                 = Event.new
-  @@OnWildPokemonCreate         = Event.new
-  @@OnWildBattleOverride        = Event.new
-  @@OnWildBattleEnd             = Event.new
-  @@OnTrainerPartyLoad          = Event.new
-  @@OnChangeDirection           = Event.new
-
-  # Fires whenever a map is created. Event handler receives two parameters: the
-  # map (RPG::Map) and the tileset (RPG::Tileset)
-  def self.onMapCreate;     @@OnMapCreate;     end
-  def self.onMapCreate=(v); @@OnMapCreate = v; end
-
-  # Fires each frame during a map update.
-  def self.onMapUpdate;     @@OnMapUpdate;     end
-  def self.onMapUpdate=(v); @@OnMapUpdate = v; end
-
-  # Fires whenever one map is about to change to a different one. Event handler
-  # receives the new map ID and the Game_Map object representing the new map.
-  # When the event handler is called, $game_map still refers to the old map.
-  def self.onMapChanging;     @@OnMapChanging;     end
-  def self.onMapChanging=(v); @@OnMapChanging = v; end
-
-  # Fires whenever the player moves to a new map. Event handler receives the old
-  # map ID or 0 if none. Also fires when the first map of the game is loaded
-  def self.onMapChange;     @@OnMapChange;     end
-  def self.onMapChange=(v); @@OnMapChange = v; end
-
-  # Fires whenever the map scene is regenerated and soon after the player moves
-  # to a new map.
-  # Parameters:
-  # e[0] - Scene_Map object.
-  # e[1] - Whether the player just moved to a new map (either true or false). If
-  #        false, some other code had called $scene.createSpritesets to
-  #        regenerate the map scene without transferring the player elsewhere
-  def self.onMapSceneChange;     @@OnMapSceneChange;     end
-  def self.onMapSceneChange=(v); @@OnMapSceneChange = v; end
-
-  # Fires whenever a spriteset is created.
-  # Parameters:
-  # e[0] - Spriteset being created. e[0].map is the map associated with the
-  #        spriteset (not necessarily the current map).
-  # e[1] - Viewport used for tilemap and characters
-  def self.onSpritesetCreate;     @@OnSpritesetCreate;     end
-  def self.onSpritesetCreate=(v); @@OnSpritesetCreate = v; end
-
-  # Triggers when the player presses the Action button on the map.
-  def self.onAction;     @@OnAction;     end
-  def self.onAction=(v); @@OnAction = v; end
-
-  # Fires whenever the player takes a step.
-  def self.onStepTaken;     @@OnStepTaken;     end
-  def self.onStepTaken=(v); @@OnStepTaken = v; end
-
-  # Fires whenever the player or another event leaves a tile.
-  # Parameters:
-  # e[0] - Event that just left the tile.
-  # e[1] - Map ID where the tile is located (not necessarily
-  #        the current map). Use "$map_factory.getMap(e[1])" to
-  #        get the Game_Map object corresponding to that map.
-  # e[2] - X-coordinate of the tile
-  # e[3] - Y-coordinate of the tile
-  def self.onLeaveTile;     @@OnLeaveTile;     end
-  def self.onLeaveTile=(v); @@OnLeaveTile = v; end
-
-  # Fires whenever the player or another event enters a tile.
-  # Parameters:
-  # e[0] - Event that just entered a tile.
-  def self.onStepTakenFieldMovement;     @@OnStepTakenFieldMovement;     end
-  def self.onStepTakenFieldMovement=(v); @@OnStepTakenFieldMovement = v; end
-
-  # Fires whenever the player takes a step. The event handler may possibly move
-  # the player elsewhere.
-  # Parameters:
-  # e[0] - Array that contains a single boolean value. If an event handler moves
-  #        the player to a new map, it should set this value to true. Other
-  #        event handlers should check this parameter's value.
-  def self.onStepTakenTransferPossible;     @@OnStepTakenTransferPossible;     end
-  def self.onStepTakenTransferPossible=(v); @@OnStepTakenTransferPossible = v; end
-
-  def self.onStartBattle;     @@OnStartBattle;     end
-  def self.onStartBattle=(v); @@OnStartBattle = v; end
-
-  def self.onEndBattle;     @@OnEndBattle;     end
-  def self.onEndBattle=(v); @@OnEndBattle = v; end
-
-  # Triggers whenever a wild Pokémon is created
-  # Parameters:
-  # e[0] - Pokémon being created
-  def self.onWildPokemonCreate;     @@OnWildPokemonCreate;     end
-  def self.onWildPokemonCreate=(v); @@OnWildPokemonCreate = v; end
-
-  # Triggers at the start of a wild battle.  Event handlers can provide their
-  # own wild battle routines to override the default behavior.
-  def self.onWildBattleOverride;     @@OnWildBattleOverride;     end
-  def self.onWildBattleOverride=(v); @@OnWildBattleOverride = v; end
-
-  # Triggers whenever a wild Pokémon battle ends
-  # Parameters:
-  # e[0] - Pokémon species
-  # e[1] - Pokémon level
-  # e[2] - Battle result (1-win, 2-loss, 3-escaped, 4-caught, 5-draw)
-  def self.onWildBattleEnd;     @@OnWildBattleEnd;     end
-  def self.onWildBattleEnd=(v); @@OnWildBattleEnd = v; end
-
-  # Triggers whenever an NPC trainer's Pokémon party is loaded
-  # Parameters:
-  # e[0] - Trainer
-  # e[1] - Items possessed by the trainer
-  # e[2] - Party
-  def self.onTrainerPartyLoad;     @@OnTrainerPartyLoad;     end
-  def self.onTrainerPartyLoad=(v); @@OnTrainerPartyLoad = v; end
-
-  # Fires whenever the player changes direction.
-  def self.onChangeDirection;     @@OnChangeDirection;     end
-  def self.onChangeDirection=(v); @@OnChangeDirection = v; end
-end
-
-#===============================================================================
-#
-#===============================================================================
-def pbOnSpritesetCreate(spriteset, viewport)
-  Events.onSpritesetCreate.trigger(nil, spriteset, viewport)
-end
-
-#===============================================================================
-# This module stores encounter-modifying events that can happen during the game.
-# A procedure can subscribe to an event by adding itself to the event. It will
-# then be called whenever the event occurs.
-#===============================================================================
-module EncounterModifier
-  @@procs    = []
-  @@procsEnd = []
-
-  def self.register(p)
-    @@procs.push(p)
-  end
-
-  def self.registerEncounterEnd(p)
-    @@procsEnd.push(p)
-  end
-
-  def self.trigger(encounter)
-    @@procs.each do |prc|
-      encounter = prc.call(encounter)
-    end
-    return encounter
-  end
-
-  def self.triggerEncounterEnd
-    @@procsEnd.each do |prc|
-      prc.call
-    end
-  end
-end
diff --git a/Data/Scripts/004_Game classes/001_Switches and Variables/001_Game_Temp.rb b/Data/Scripts/004_Game classes/001_Switches and Variables/001_Game_Temp.rb
index ce1627aa5..4e3d285a0 100644
--- a/Data/Scripts/004_Game classes/001_Switches and Variables/001_Game_Temp.rb	
+++ b/Data/Scripts/004_Game classes/001_Switches and Variables/001_Game_Temp.rb	
@@ -9,7 +9,7 @@ class Game_Temp
   attr_accessor :menu_calling             # menu calling flag
   attr_accessor :ready_menu_calling       # ready menu calling flag
   attr_accessor :debug_calling            # debug calling flag
-  attr_accessor :interact_calling         # trigger Events.onAction flag
+  attr_accessor :interact_calling         # EventHandlers.trigger(:on_player_interact) flag
   attr_accessor :battle_abort             # battle flag: interrupt (unused)
   attr_accessor :title_screen_calling     # return to title screen flag
   attr_accessor :common_event_id          # common event ID to start
diff --git a/Data/Scripts/004_Game classes/004_Game_Map.rb b/Data/Scripts/004_Game classes/004_Game_Map.rb
index c6e9b6af4..b11e96041 100644
--- a/Data/Scripts/004_Game classes/004_Game_Map.rb	
+++ b/Data/Scripts/004_Game classes/004_Game_Map.rb	
@@ -57,7 +57,7 @@ class Game_Map
     self.display_x        = 0
     self.display_y        = 0
     @need_refresh         = false
-    Events.onMapCreate.trigger(self, map_id, @map, tileset)
+    EventHandlers.trigger(:on_game_map_setup, map_id, @map, tileset)
     @events               = {}
     @map.events.keys.each do |i|
       @events[i]          = Game_Event.new(@map_id, @map.events[i], self)
diff --git a/Data/Scripts/004_Game classes/006_Game_MapFactory.rb b/Data/Scripts/004_Game classes/006_Game_MapFactory.rb
index bf0a72af8..3a6c48caf 100644
--- a/Data/Scripts/004_Game classes/006_Game_MapFactory.rb	
+++ b/Data/Scripts/004_Game classes/006_Game_MapFactory.rb	
@@ -145,16 +145,16 @@ class PokemonMapFactory
   end
 
   def setMapChanging(newID, newMap)
-    Events.onMapChanging.trigger(self, newID, newMap)
+    EventHandlers.trigger(:on_leave_map, newID, newMap)
   end
 
   def setMapChanged(prevMap)
-    Events.onMapChange.trigger(self, prevMap)
+    EventHandlers.trigger(:on_enter_map, prevMap)
     @mapChanged = true
   end
 
   def setSceneStarted(scene)
-    Events.onMapSceneChange.trigger(self, scene, @mapChanged)
+    EventHandlers.trigger(:on_map_or_spriteset_change, scene, @mapChanged)
     @mapChanged = false
   end
 
diff --git a/Data/Scripts/004_Game classes/007_Game_Character.rb b/Data/Scripts/004_Game classes/007_Game_Character.rb
index 757e9e934..83a44b806 100644
--- a/Data/Scripts/004_Game classes/007_Game_Character.rb	
+++ b/Data/Scripts/004_Game classes/007_Game_Character.rb	
@@ -382,7 +382,7 @@ class Game_Character
   def triggerLeaveTile
     if @oldX && @oldY && @oldMap &&
        (@oldX != self.x || @oldY != self.y || @oldMap != self.map.map_id)
-      Events.onLeaveTile.trigger(self, self, @oldMap, @oldX, @oldY)
+      EventHandlers.trigger(:on_leave_tile, self, @oldMap, @oldX, @oldY)
     end
     @oldX = self.x
     @oldY = self.y
@@ -918,7 +918,7 @@ class Game_Character
     end
     # End of a step, so perform events that happen at this time
     if !jumping? && !moving?
-      Events.onStepTakenFieldMovement.trigger(self, self)
+      EventHandlers.trigger(:on_step_taken, self)
       calculate_bush_depth
       @stopped_this_frame = true
     elsif !@moved_last_frame || @stopped_last_frame   # Started a new step
diff --git a/Data/Scripts/004_Game classes/009_Game_Player.rb b/Data/Scripts/004_Game classes/009_Game_Player.rb
index 9984a5205..6d2022972 100644
--- a/Data/Scripts/004_Game classes/009_Game_Player.rb	
+++ b/Data/Scripts/004_Game classes/009_Game_Player.rb	
@@ -141,7 +141,7 @@ class Game_Player < Game_Character
     old_direction = @direction
     super(dir)
     if @direction != old_direction && !@move_route_forcing && !pbMapInterpreterRunning?
-      Events.onChangeDirection.trigger(self, self)
+      EventHandlers.trigger(:on_player_change_direction)
       $game_temp.encounter_triggered = false if !keep_enc_indicator
     end
   end
diff --git a/Data/Scripts/005_Sprites/007_Spriteset_Map.rb b/Data/Scripts/005_Sprites/007_Spriteset_Map.rb
index 9be78e3a9..09fc2bc11 100644
--- a/Data/Scripts/005_Sprites/007_Spriteset_Map.rb
+++ b/Data/Scripts/005_Sprites/007_Spriteset_Map.rb
@@ -59,7 +59,7 @@ class Spriteset_Map
       @character_sprites.push(sprite)
     end
     @weather = RPG::Weather.new(@@viewport1)
-    pbOnSpritesetCreate(self, @@viewport1)
+    EventHandlers.trigger(:on_new_spriteset_map, self, @@viewport1)
     update
   end
 
diff --git a/Data/Scripts/010_Data/001_Hardcoded data/011_TerrainTag.rb b/Data/Scripts/010_Data/001_Hardcoded data/011_TerrainTag.rb
index dd737bebd..575dee5ef 100644
--- a/Data/Scripts/010_Data/001_Hardcoded data/011_TerrainTag.rb	
+++ b/Data/Scripts/010_Data/001_Hardcoded data/011_TerrainTag.rb	
@@ -170,8 +170,9 @@ GameData::TerrainTag.register({
   :ignore_passability     => true
 })
 
-# NOTE: This is referenced by ID in an Events.onStepTakenFieldMovement proc that
-#       adds soot to the Soot Sack if the player walks over one of these tiles.
+# NOTE: This is referenced by ID in the :pick_up_soot proc added to
+#       EventHandlers. It adds soot to the Soot Sack if the player walks over
+#       one of these tiles.
 GameData::TerrainTag.register({
   :id                     => :SootGrass,
   :id_number              => 14,
diff --git a/Data/Scripts/012_Overworld/001_Overworld visuals/002_Overworld_Overlays.rb b/Data/Scripts/012_Overworld/001_Overworld visuals/002_Overworld_Overlays.rb
index 68ba42f30..0ba7e1c61 100644
--- a/Data/Scripts/012_Overworld/001_Overworld visuals/002_Overworld_Overlays.rb	
+++ b/Data/Scripts/012_Overworld/001_Overworld visuals/002_Overworld_Overlays.rb	
@@ -205,22 +205,22 @@ end
 
 
 
-Events.onSpritesetCreate += proc { |_sender, e|
-  spriteset = e[0]      # Spriteset being created
-  viewport  = e[1]      # Viewport used for tilemap and characters
-  map = spriteset.map   # Map associated with the spriteset (not necessarily the current map)
-  map.events.keys.each do |i|
-    if map.events[i].name[/^outdoorlight\((\w+)\)$/i]
-      filename = $~[1].to_s
-      spriteset.addUserSprite(LightEffect_DayNight.new(map.events[i], viewport, map, filename))
-    elsif map.events[i].name[/^outdoorlight$/i]
-      spriteset.addUserSprite(LightEffect_DayNight.new(map.events[i], viewport, map))
-    elsif map.events[i].name[/^light\((\w+)\)$/i]
-      filename = $~[1].to_s
-      spriteset.addUserSprite(LightEffect_Basic.new(map.events[i], viewport, map, filename))
-    elsif map.events[i].name[/^light$/i]
-      spriteset.addUserSprite(LightEffect_Basic.new(map.events[i], viewport, map))
+EventHandlers.add(:on_new_spriteset_map, :add_light_effects,
+  proc { |spriteset, viewport|
+    map = spriteset.map   # Map associated with the spriteset (not necessarily the current map)
+    map.events.keys.each do |i|
+      if map.events[i].name[/^outdoorlight\((\w+)\)$/i]
+        filename = $~[1].to_s
+        spriteset.addUserSprite(LightEffect_DayNight.new(map.events[i], viewport, map, filename))
+      elsif map.events[i].name[/^outdoorlight$/i]
+        spriteset.addUserSprite(LightEffect_DayNight.new(map.events[i], viewport, map))
+      elsif map.events[i].name[/^light\((\w+)\)$/i]
+        filename = $~[1].to_s
+        spriteset.addUserSprite(LightEffect_Basic.new(map.events[i], viewport, map, filename))
+      elsif map.events[i].name[/^light$/i]
+        spriteset.addUserSprite(LightEffect_Basic.new(map.events[i], viewport, map))
+      end
     end
-  end
-  spriteset.addUserSprite(Particle_Engine.new(viewport, map))
-}
+    spriteset.addUserSprite(Particle_Engine.new(viewport, map))
+  }
+)
diff --git a/Data/Scripts/012_Overworld/001_Overworld.rb b/Data/Scripts/012_Overworld/001_Overworld.rb
index 552746f98..8e36aef11 100644
--- a/Data/Scripts/012_Overworld/001_Overworld.rb
+++ b/Data/Scripts/012_Overworld/001_Overworld.rb
@@ -2,17 +2,18 @@
 # Constant checks
 #===============================================================================
 # Pokérus check
-Events.onMapUpdate += proc { |_sender, _e|
-  next if !$player
-  last = $PokemonGlobal.pokerusTime
-  now = pbGetTimeNow
-  if !last || last.year != now.year || last.month != now.month || last.day != now.day
-    $player.pokemon_party.each do |i|
-      i.lowerPokerusCount
+EventHandlers.add(:on_frame_update, :pokerus_counter,
+  proc {
+    next if !$player
+    last = $PokemonGlobal.pokerusTime
+    next if !last
+    now = pbGetTimeNow
+    if last.year != now.year || last.month != now.month || last.day != now.day
+      $player.pokemon_party.each { |pkmn| pkmn.lowerPokerusCount }
+      $PokemonGlobal.pokerusTime = now
     end
-    $PokemonGlobal.pokerusTime = now
-  end
-}
+  }
+)
 
 # Returns whether the Poké Center should explain Pokérus to the player, if a
 # healed Pokémon has it.
@@ -46,70 +47,74 @@ def pbBatteryLow?
   return false
 end
 
-Events.onMapUpdate += proc { |_sender, _e|
-  if !$game_temp.warned_low_battery && pbBatteryLow? &&
-     !$game_temp.in_menu && !$game_temp.in_battle && !$game_player.move_route_forcing &&
-     !$game_temp.message_window_showing && !pbMapInterpreterRunning? &&
-     pbGetTimeNow.sec == 0
-    pbMessage(_INTL("The game has detected that the battery is low. You should save soon to avoid losing your progress."))
+EventHandlers.add(:on_frame_update, :low_battery_warning,
+  proc {
+    next if $game_temp.warned_low_battery || !pbBatteryLow?
+    next if $game_temp.in_menu || $game_temp.in_battle || $game_player.move_route_forcing ||
+            $game_temp.message_window_showing || pbMapInterpreterRunning?
+    next if pbGetTimeNow.sec != 0
     $game_temp.warned_low_battery = true
-  end
-  if $game_temp.cue_bgm_frame_delay
+    pbMessage(_INTL("The game has detected that the battery is low. You should save soon to avoid losing your progress."))
+  }
+)
+
+EventHandlers.add(:on_frame_update, :cue_bgm_after_delay,
+  proc {
+    next if $game_temp.cue_bgm_frame_delay.nil?
     $game_temp.cue_bgm_frame_delay -= 1
-    if $game_temp.cue_bgm_frame_delay <= 0
-      $game_temp.cue_bgm_frame_delay = nil
-      pbBGMPlay($game_temp.cue_bgm) if $game_system.getPlayingBGM.nil?
-    end
-  end
-}
-
-
+    next if $game_temp.cue_bgm_frame_delay > 0
+    $game_temp.cue_bgm_frame_delay = nil
+    pbBGMPlay($game_temp.cue_bgm) if $game_system.getPlayingBGM.nil?
+  }
+)
 
 #===============================================================================
 # Checks per step
 #===============================================================================
 # Party Pokémon gain happiness from walking
-Events.onStepTaken += proc {
-  $PokemonGlobal.happinessSteps = 0 if !$PokemonGlobal.happinessSteps
-  $PokemonGlobal.happinessSteps += 1
-  if $PokemonGlobal.happinessSteps >= 128
+EventHandlers.add(:on_player_step_taken, :gain_happiness,
+  proc {
+    $PokemonGlobal.happinessSteps = 0 if !$PokemonGlobal.happinessSteps
+    $PokemonGlobal.happinessSteps += 1
+    next if $PokemonGlobal.happinessSteps < 128
     $player.able_party.each do |pkmn|
       pkmn.changeHappiness("walking") if rand(2) == 0
     end
     $PokemonGlobal.happinessSteps = 0
-  end
-}
+  }
+)
 
 # Poison party Pokémon
-Events.onStepTakenTransferPossible += proc { |_sender, e|
-  handled = e[0]
-  next if handled[0]
-  if $PokemonGlobal.stepcount % 4 == 0 && Settings::POISON_IN_FIELD
+EventHandlers.add(:on_player_step_taken_can_transfer, :poison_party,
+  proc { |handled|
+    # handled is an array: [nil]. If [true], a message has already been shown
+    # because of this step, so don't do anything that might show another one
+    next if handled[0]
+    next if !Settings::POISON_IN_FIELD || $PokemonGlobal.stepcount % 4 != 0
     flashed = false
-    $player.able_party.each do |i|
-      if i.status == :POISON && !i.hasAbility?(:IMMUNITY)
-        if !flashed
-          pbFlash(Color.new(255, 0, 0, 128), 8)
-          flashed = true
-        end
-        i.hp -= 1 if i.hp > 1 || Settings::POISON_FAINT_IN_FIELD
-        if i.hp == 1 && !Settings::POISON_FAINT_IN_FIELD
-          i.status = :NONE
-          pbMessage(_INTL("{1} survived the poisoning.\\nThe poison faded away!\1", i.name))
-          next
-        elsif i.hp == 0
-          i.changeHappiness("faint")
-          i.status = :NONE
-          pbMessage(_INTL("{1} fainted...", i.name))
-        end
-        if $player.able_pokemon_count == 0
-          handled[0] = true
-          pbCheckAllFainted
-        end
+    $player.able_party.each do |pkmn|
+      next if pkmn.status != :POISON || pkmn.hasAbility?(:IMMUNITY)
+      if !flashed
+        pbFlash(Color.new(255, 0, 0, 128), 8)
+        flashed = true
+      end
+      pkmn.hp -= 1 if pkmn.hp > 1 || Settings::POISON_FAINT_IN_FIELD
+      if pkmn.hp == 1 && !Settings::POISON_FAINT_IN_FIELD
+        pkmn.status = :NONE
+        pbMessage(_INTL("{1} survived the poisoning.\\nThe poison faded away!\1", pkmn.name))
+        next
+      elsif pkmn.hp == 0
+        pkmn.changeHappiness("faint")
+        pkmn.status = :NONE
+        pbMessage(_INTL("{1} fainted...", pkmn.name))
+      end
+      if $player.able_pokemon_count == 0
+        handled[0] = true
+        pbCheckAllFainted
       end
     end
-  end
-}
+  }
+)
 
 def pbCheckAllFainted
   if $player.able_pokemon_count == 0
@@ -122,67 +127,74 @@ def pbCheckAllFainted
 end
 
 # Gather soot from soot grass
-Events.onStepTakenFieldMovement += proc { |_sender, e|
-  event = e[0]   # Get the event affected by field movement
-  thistile = $map_factory.getRealTilePos(event.map.map_id, event.x, event.y)
-  map = $map_factory.getMap(thistile[0])
-  [2, 1, 0].each do |i|
-    tile_id = map.data[thistile[1], thistile[2], i]
-    next if tile_id.nil?
-    next if GameData::TerrainTag.try_get(map.terrain_tags[tile_id]).id != :SootGrass
-    if event == $game_player && $bag.has?(:SOOTSACK)
-      old_soot = $player.soot
-      $player.soot += 1
-      $stats.soot_collected += $player.soot - old_soot if $player.soot > old_soot
+EventHandlers.add(:on_step_taken, :pick_up_soot,
+  proc { |event|
+    thistile = $map_factory.getRealTilePos(event.map.map_id, event.x, event.y)
+    map = $map_factory.getMap(thistile[0])
+    [2, 1, 0].each do |i|
+      tile_id = map.data[thistile[1], thistile[2], i]
+      next if tile_id.nil?
+      next if GameData::TerrainTag.try_get(map.terrain_tags[tile_id]).id != :SootGrass
+      if event == $game_player && $bag.has?(:SOOTSACK)
+        old_soot = $player.soot
+        $player.soot += 1
+        $stats.soot_collected += $player.soot - old_soot if $player.soot > old_soot
+      end
+      map.erase_tile(thistile[1], thistile[2], i)
+      break
     end
-    map.erase_tile(thistile[1], thistile[2], i)
-    break
-  end
-}
+  }
+)
 
-# Show grass rustle animation, and auto-move the player over waterfalls and ice
-Events.onStepTakenFieldMovement += proc { |_sender, e|
-  event = e[0]   # Get the event affected by field movement
-  if $scene.is_a?(Scene_Map)
+# Show grass rustle animation
+EventHandlers.add(:on_step_taken, :grass_rustling,
+  proc { |event|
+    next if !$scene.is_a?(Scene_Map)
     event.each_occupied_tile do |x, y|
-      if $map_factory.getTerrainTag(event.map.map_id, x, y, true).shows_grass_rustle
-        $scene.spriteset.addUserAnimation(Settings::GRASS_ANIMATION_ID, x, y, true, 1)
-      end
+      next if !$map_factory.getTerrainTag(event.map.map_id, x, y, true).shows_grass_rustle
+      $scene.spriteset.addUserAnimation(Settings::GRASS_ANIMATION_ID, x, y, true, 1)
     end
-    if event == $game_player
-      currentTag = $game_player.pbTerrainTag
-      if currentTag.waterfall_crest
-        pbDescendWaterfall
-      elsif currentTag.ice && !$PokemonGlobal.sliding
-        pbSlideOnIce
-      end
+  }
+)
+
+# Auto-move the player over waterfalls and ice
+EventHandlers.add(:on_step_taken, :auto_move_player,
+  proc { |event|
+    next if !$scene.is_a?(Scene_Map)
+    next if event != $game_player
+    currentTag = $game_player.pbTerrainTag
+    if currentTag.waterfall_crest
+      pbDescendWaterfall
+    elsif currentTag.ice && !$PokemonGlobal.sliding
+      pbSlideOnIce
     end
-  end
-}
+  }
+)
 
 def pbOnStepTaken(eventTriggered)
   if $game_player.move_route_forcing || pbMapInterpreterRunning?
-    Events.onStepTakenFieldMovement.trigger(nil, $game_player)
+    EventHandlers.trigger(:on_step_taken, $game_player)
     return
   end
   $PokemonGlobal.stepcount = 0 if !$PokemonGlobal.stepcount
   $PokemonGlobal.stepcount += 1
   $PokemonGlobal.stepcount &= 0x7FFFFFFF
   repel_active = ($PokemonGlobal.repel > 0)
-  Events.onStepTaken.trigger(nil)
-#  Events.onStepTakenFieldMovement.trigger(nil,$game_player)
+  EventHandlers.trigger(:on_player_step_taken)
   handled = [nil]
-  Events.onStepTakenTransferPossible.trigger(nil, handled)
+  EventHandlers.trigger(:on_player_step_taken_can_transfer, handled)
   return if handled[0]
   pbBattleOnStepTaken(repel_active) if !eventTriggered && !$game_temp.in_menu
   $game_temp.encounter_triggered = false   # This info isn't needed here
 end
 
 # Start wild encounters while turning on the spot
-Events.onChangeDirection += proc {
-  repel_active = ($PokemonGlobal.repel > 0)
-  pbBattleOnStepTaken(repel_active) if !$game_temp.in_menu
-}
+EventHandlers.add(:on_player_change_direction, :trigger_encounter,
+  proc {
+    repel_active = ($PokemonGlobal.repel > 0)
+    pbBattleOnStepTaken(repel_active) if !$game_temp.in_menu
+  }
+)
 
 def pbBattleOnStepTaken(repel_active)
   return if $player.able_pokemon_count == 0
@@ -192,11 +204,11 @@ def pbBattleOnStepTaken(repel_active)
   return if !$PokemonEncounters.encounter_triggered?(encounter_type, repel_active)
   $game_temp.encounter_type = encounter_type
   encounter = $PokemonEncounters.choose_wild_pokemon(encounter_type)
-  encounter = EncounterModifier.trigger(encounter)
+  EventHandlers.trigger(:on_wild_species_chosen, encounter)
   if $PokemonEncounters.allow_encounter?(encounter, repel_active)
     if $PokemonEncounters.have_double_wild_battle?
       encounter2 = $PokemonEncounters.choose_wild_pokemon(encounter_type)
-      encounter2 = EncounterModifier.trigger(encounter2)
+      EventHandlers.trigger(:on_wild_species_chosen, encounter2)
       pbDoubleWildBattle(encounter[0], encounter[1], encounter2[0], encounter2[1])
     else
       pbWildBattle(encounter[0], encounter[1])
@@ -205,7 +217,6 @@ def pbBattleOnStepTaken(repel_active)
     $game_temp.encounter_triggered = true
   end
   $game_temp.force_single_battle = false
-  EncounterModifier.triggerEncounterEnd
 end
 
 
@@ -216,67 +227,94 @@ end
 # Clears the weather of the old map, if the old map has defined weather and the
 # new map either has the same name as the old map or doesn't have defined
 # weather.
-Events.onMapChanging += proc { |_sender, e|
-  new_map_ID = e[0]
-  next if new_map_ID == 0
-  old_map_metadata = $game_map.metadata
-  next if !old_map_metadata || !old_map_metadata.weather
-  map_infos = pbLoadMapInfos
-  if $game_map.name == map_infos[new_map_ID].name
-    new_map_metadata = GameData::MapMetadata.try_get(new_map_ID)
-    next if new_map_metadata&.weather
-  end
-  $game_screen.weather(:None, 0, 0)
-}
+EventHandlers.add(:on_leave_map, :end_weather,
+  proc { |new_map_id, new_map|
+    next if new_map_id == 0
+    old_map_metadata = $game_map.metadata
+    next if !old_map_metadata || !old_map_metadata.weather
+    map_infos = pbLoadMapInfos
+    if $game_map.name == map_infos[new_map_id].name
+      new_map_metadata = GameData::MapMetadata.try_get(new_map_id)
+      next if new_map_metadata&.weather
+    end
+    $game_screen.weather(:None, 0, 0)
+  }
+)
 
 # Set up various data related to the new map
-Events.onMapChange += proc { |_sender, e|
-  old_map_ID = e[0]   # previous map ID, is 0 if no map ID
-  new_map_metadata = $game_map.metadata
-  if new_map_metadata&.teleport_destination
-    $PokemonGlobal.healingSpot = new_map_metadata.teleport_destination
-  end
-  $PokemonMap&.clear
-  $PokemonEncounters&.setup($game_map.map_id)
-  $PokemonGlobal.visitedMaps[$game_map.map_id] = true
-  next if old_map_ID == 0 || old_map_ID == $game_map.map_id
-  next if !new_map_metadata || !new_map_metadata.weather
-  map_infos = pbLoadMapInfos
-  if $game_map.name == map_infos[old_map_ID].name
-    old_map_metadata = GameData::MapMetadata.try_get(old_map_ID)
-    next if old_map_metadata&.weather
-  end
-  new_weather = new_map_metadata.weather
-  $game_screen.weather(new_weather[0], 9, 0) if rand(100) < new_weather[1]
-}
+EventHandlers.add(:on_enter_map, :setup_new_map,
+  proc { |old_map_id|   # previous map ID, is 0 if no map ID
+    # Record new Teleport destination
+    new_map_metadata = $game_map.metadata
+    if new_map_metadata&.teleport_destination
+      $PokemonGlobal.healingSpot = new_map_metadata.teleport_destination
+    end
+    # End effects that apply only while on the map they were used
+    $PokemonMap&.clear
+    # Setup new wild encounter tables
+    $PokemonEncounters&.setup($game_map.map_id)
+    # Record the new map as having been visited
+    $PokemonGlobal.visitedMaps[$game_map.map_id] = true
+    # Set weather if new map has weather
+    next if old_map_id == 0 || old_map_id == $game_map.map_id
+    next if !new_map_metadata || !new_map_metadata.weather
+    map_infos = pbLoadMapInfos
+    if $game_map.name == map_infos[old_map_id].name
+      old_map_metadata = GameData::MapMetadata.try_get(old_map_id)
+      next if old_map_metadata&.weather
+    end
+    new_weather = new_map_metadata.weather
+    $game_screen.weather(new_weather[0], 9, 0) if rand(100) < new_weather[1]
+  }
+)
 
-Events.onMapSceneChange += proc { |_sender, e|
-  scene      = e[0]
-  mapChanged = e[1]
-  next if !scene || !scene.spriteset
-  # Update map trail
-  if $game_map
+# Update trail of which maps the player has most recently visited.
+EventHandlers.add(:on_enter_map, :add_to_trail,
+  proc { |_old_map_id|
+    next if !$game_map
     $PokemonGlobal.mapTrail = [] if !$PokemonGlobal.mapTrail
     if $PokemonGlobal.mapTrail[0] != $game_map.map_id && $PokemonGlobal.mapTrail.length >= 4
       $PokemonGlobal.mapTrail.pop
     end
     $PokemonGlobal.mapTrail = [$game_map.map_id] + $PokemonGlobal.mapTrail
-  end
-  # Display darkness circle on dark maps
-  map_metadata = $game_map.metadata
-  if map_metadata&.dark_map
-    $game_temp.darkness_sprite = DarknessSprite.new
-    scene.spriteset.addUserSprite($game_temp.darkness_sprite)
-    if $PokemonGlobal.flashUsed
-      $game_temp.darkness_sprite.radius = $game_temp.darkness_sprite.radiusMax
+  }
+)
+
+# Force cycling/walking.
+EventHandlers.add(:on_enter_map, :force_cycling,
+  proc { |_old_map_id|
+    if $game_map.metadata&.always_bicycle
+      pbMountBike
+    elsif !pbCanUseBike?($game_map.map_id)
+      pbDismountBike
     end
-  else
-    $PokemonGlobal.flashUsed = false
-    $game_temp.darkness_sprite&.dispose
-    $game_temp.darkness_sprite = nil
-  end
-  # Show location signpost
-  if mapChanged && map_metadata && map_metadata.announce_location
+  }
+)
+
+# Display darkness circle on dark maps.
+EventHandlers.add(:on_map_or_spriteset_change, :show_darkness,
+  proc { |scene, _map_changed|
+    next if !scene || !scene.spriteset
+    map_metadata = $game_map.metadata
+    if map_metadata&.dark_map
+      $game_temp.darkness_sprite = DarknessSprite.new
+      scene.spriteset.addUserSprite($game_temp.darkness_sprite)
+      if $PokemonGlobal.flashUsed
+        $game_temp.darkness_sprite.radius = $game_temp.darkness_sprite.radiusMax
+      end
+    else
+      $PokemonGlobal.flashUsed = false
+      $game_temp.darkness_sprite&.dispose
+      $game_temp.darkness_sprite = nil
+    end
+  }
+)
+
+# Show location signpost.
+EventHandlers.add(:on_map_or_spriteset_change, :show_location_window,
+  proc { |scene, map_changed|
+    next if !scene || !scene.spriteset
+    next if !map_changed || !$game_map.metadata&.announce_location
     nosignpost = false
     if $PokemonGlobal.mapTrail[1]
       (Settings::NO_SIGNPOSTS.length / 2).times do |i|
@@ -291,14 +329,8 @@ Events.onMapSceneChange += proc { |_sender, e|
       nosignpost = true if $game_map.name == oldmapname
     end
     scene.spriteset.addUserSprite(LocationWindow.new($game_map.name)) if !nosignpost
-  end
-  # Force cycling/walking
-  if map_metadata&.always_bicycle
-    pbMountBike
-  elsif !pbCanUseBike?($game_map.map_id)
-    pbDismountBike
-  end
-}
+  }
+)
 
 
 
@@ -683,7 +715,7 @@ def pbRegisterPartner(tr_type, tr_name, tr_id = 0)
   tr_type = GameData::TrainerType.get(tr_type).id
   pbCancelVehicles
   trainer = pbLoadTrainer(tr_type, tr_name, tr_id)
-  Events.onTrainerPartyLoad.trigger(nil, trainer)
+  EventHandlers.trigger(:on_trainer_load, trainer)
   trainer.party.each do |i|
     i.owner = Pokemon::Owner.new_from_trainer(trainer)
     i.calc_stats
diff --git a/Data/Scripts/012_Overworld/002_Battle triggering/001_Overworld_BattleStarting.rb b/Data/Scripts/012_Overworld/002_Battle triggering/001_Overworld_BattleStarting.rb
index f0a2e8e2c..5ea0469f7 100644
--- a/Data/Scripts/012_Overworld/002_Battle triggering/001_Overworld_BattleStarting.rb	
+++ b/Data/Scripts/012_Overworld/002_Battle triggering/001_Overworld_BattleStarting.rb	
@@ -188,18 +188,20 @@ def pbGetEnvironment
   return ret
 end
 
-Events.onStartBattle += proc { |_sender|
-  # Record current levels of Pokémon in party, to see if they gain a level
-  # during battle and may need to evolve afterwards
-  $game_temp.party_levels_before_battle = []
-  $game_temp.party_critical_hits_dealt = []
-  $game_temp.party_direct_damage_taken = []
-  $player.party.each_with_index do |pkmn, i|
-    $game_temp.party_levels_before_battle[i] = pkmn.level
-    $game_temp.party_critical_hits_dealt[i] = 0
-    $game_temp.party_direct_damage_taken[i] = 0
-  end
-}
+# Record current levels of Pokémon in party, to see if they gain a level during
+# battle and may need to evolve afterwards
+EventHandlers.add(:on_start_battle, :record_party_status,
+  proc {
+    $game_temp.party_levels_before_battle = []
+    $game_temp.party_critical_hits_dealt = []
+    $game_temp.party_direct_damage_taken = []
+    $player.party.each_with_index do |pkmn, i|
+      $game_temp.party_levels_before_battle[i] = pkmn.level
+      $game_temp.party_critical_hits_dealt[i] = 0
+      $game_temp.party_direct_damage_taken[i] = 0
+    end
+  }
+)
 
 def pbCanDoubleBattle?
   return $PokemonGlobal.partner || $player.able_pokemon_count >= 2
@@ -230,7 +232,7 @@ def pbWildBattleCore(*args)
   end
   # Record information about party Pokémon to be used at the end of battle (e.g.
   # comparing levels for an evolution check)
-  Events.onStartBattle.trigger(nil)
+  EventHandlers.trigger(:on_start_battle)
   # Generate wild Pokémon based on the species and level
   foeParty = []
   sp = nil
@@ -314,8 +316,8 @@ def pbWildBattle(species, level, outcomeVar = 1, canRun = true, canLose = false)
   # Potentially call a different pbWildBattle-type method instead (for roaming
   # Pokémon, Safari battles, Bug Contest battles)
   handled = [nil]
-  Events.onWildBattleOverride.trigger(nil, species, level, handled)
-  return handled[0] if handled[0] != nil
+  EventHandlers.trigger(:on_calling_wild_battle, species, level, handled)
+  return handled[0] if !handled[0].nil?
   # Set some battle rules
   setBattleRule("outcomeVar", outcomeVar) if outcomeVar != 1
   setBattleRule("cannotRun") if !canRun
@@ -323,7 +325,7 @@ def pbWildBattle(species, level, outcomeVar = 1, canRun = true, canLose = false)
   # Perform the battle
   decision = pbWildBattleCore(species, level)
   # Used by the Poké Radar to update/break the chain
-  Events.onWildBattleEnd.trigger(nil, species, level, decision)
+  EventHandlers.trigger(:on_wild_battle_end, species, level, decision)
   # Return false if the player lost or drew the battle, and true if any other result
   return (decision != 2 && decision != 5)
 end
@@ -375,7 +377,7 @@ def pbTrainerBattleCore(*args)
   end
   # Record information about party Pokémon to be used at the end of battle (e.g.
   # comparing levels for an evolution check)
-  Events.onStartBattle.trigger(nil)
+  EventHandlers.trigger(:on_start_battle)
   # Generate trainers and their parties based on the arguments given
   foeTrainers    = []
   foeItems       = []
@@ -394,7 +396,7 @@ def pbTrainerBattleCore(*args)
       trainer = pbLoadTrainer(arg[0], arg[1], arg[2])
       pbMissingTrainer(arg[0], arg[1], arg[2]) if !trainer
       return 0 if !trainer
-      Events.onTrainerPartyLoad.trigger(nil, trainer)
+      EventHandlers.trigger(:on_trainer_load, trainer)
       foeTrainers.push(trainer)
       foePartyStarts.push(foeParty.length)
       trainer.party.each { |pkmn| foeParty.push(pkmn) }
@@ -495,7 +497,7 @@ def pbTrainerBattle(trainerID, trainerName, endSpeech = nil,
     trainer = pbLoadTrainer(trainerID, trainerName, trainerPartyID)
     pbMissingTrainer(trainerID, trainerName, trainerPartyID) if !trainer
     return false if !trainer
-    Events.onTrainerPartyLoad.trigger(nil, trainer)
+    EventHandlers.trigger(:on_trainer_load, trainer)
     # If there is exactly 1 other triggered trainer event, and this trainer has
     # 6 or fewer Pokémon, record this trainer for a double battle caused by the
     # other triggered trainer event
@@ -580,34 +582,34 @@ def pbAfterBattle(decision, canLose)
     $player.party.each { |pkmn| pkmn.heal }
     (Graphics.frame_rate / 4).times { Graphics.update }
   end
-  Events.onEndBattle.trigger(nil, decision, canLose)
+  EventHandlers.trigger(:on_end_battle, decision, canLose)
   $game_player.straighten
 end
 
-Events.onEndBattle += proc { |_sender, e|
-  decision = e[0]
-  canLose  = e[1]
-  # Check for evolutions
-  pbEvolutionCheck if Settings::CHECK_EVOLUTION_AFTER_ALL_BATTLES ||
-                      (decision != 2 && decision != 5)   # not a loss or a draw
-  $game_temp.party_levels_before_battle = nil
-  $game_temp.party_critical_hits_dealt = nil
-  $game_temp.party_direct_damage_taken = nil
-  # Check for blacking out or gaining Pickup/Huney Gather items
-  case decision
-  when 1, 4   # Win, capture
-    $player.pokemon_party.each do |pkmn|
-      pbPickup(pkmn)
-      pbHoneyGather(pkmn)
+EventHandlers.add(:on_end_battle, :evolve_and_black_out,
+  proc { |decision, canLose|
+    # Check for evolutions
+    pbEvolutionCheck if Settings::CHECK_EVOLUTION_AFTER_ALL_BATTLES ||
+                        (decision != 2 && decision != 5)   # not a loss or a draw
+    $game_temp.party_levels_before_battle = nil
+    $game_temp.party_critical_hits_dealt = nil
+    $game_temp.party_direct_damage_taken = nil
+    # Check for blacking out or gaining Pickup/Huney Gather items
+    case decision
+    when 1, 4   # Win, capture
+      $player.pokemon_party.each do |pkmn|
+        pbPickup(pkmn)
+        pbHoneyGather(pkmn)
+      end
+    when 2, 5   # Lose, draw
+      if !canLose
+        $game_system.bgm_unpause
+        $game_system.bgs_unpause
+        pbStartOver
+      end
     end
-  when 2, 5   # Lose, draw
-    if !canLose
-      $game_system.bgm_unpause
-      $game_system.bgs_unpause
-      pbStartOver
-    end
-  end
-}
+  }
+)
 
 def pbEvolutionCheck
   $player.party.each_with_index do |pkmn, i|
diff --git a/Data/Scripts/012_Overworld/002_Battle triggering/003_Overworld_WildEncounters.rb b/Data/Scripts/012_Overworld/002_Battle triggering/003_Overworld_WildEncounters.rb
index 02ce86a2e..45f21a9ce 100644
--- a/Data/Scripts/012_Overworld/002_Battle triggering/003_Overworld_WildEncounters.rb	
+++ b/Data/Scripts/012_Overworld/002_Battle triggering/003_Overworld_WildEncounters.rb	
@@ -446,7 +446,7 @@ def pbGenerateWildPokemon(species, level, isRoamer = false)
     end
   end
   # Trigger events that may alter the generated Pokémon further
-  Events.onWildPokemonCreate.trigger(nil, genwildpoke)
+  EventHandlers.trigger(:on_wild_pokemon_created, genwildpoke)
   return genwildpoke
 end
 
@@ -455,11 +455,11 @@ end
 def pbEncounter(enc_type)
   $game_temp.encounter_type = enc_type
   encounter1 = $PokemonEncounters.choose_wild_pokemon(enc_type)
-  encounter1 = EncounterModifier.trigger(encounter1)
+  EventHandlers.trigger(:on_wild_species_chosen, encounter1)
   return false if !encounter1
   if $PokemonEncounters.have_double_wild_battle?
     encounter2 = $PokemonEncounters.choose_wild_pokemon(enc_type)
-    encounter2 = EncounterModifier.trigger(encounter2)
+    EventHandlers.trigger(:on_wild_species_chosen, encounter2)
     return false if !encounter2
     pbDoubleWildBattle(encounter1[0], encounter1[1], encounter2[0], encounter2[1])
   else
@@ -467,6 +467,5 @@ def pbEncounter(enc_type)
   end
   $game_temp.encounter_type = nil
   $game_temp.force_single_battle = false
-  EncounterModifier.triggerEncounterEnd
   return true
 end
diff --git a/Data/Scripts/012_Overworld/002_Battle triggering/004_Overworld_EncounterModifiers.rb b/Data/Scripts/012_Overworld/002_Battle triggering/004_Overworld_EncounterModifiers.rb
index 203c76027..d1c3d6b1b 100644
--- a/Data/Scripts/012_Overworld/002_Battle triggering/004_Overworld_EncounterModifiers.rb	
+++ b/Data/Scripts/012_Overworld/002_Battle triggering/004_Overworld_EncounterModifiers.rb	
@@ -6,35 +6,36 @@
 ################################################################################
 
 # Make all wild Pokémon shiny while a certain Switch is ON (see Settings).
-Events.onWildPokemonCreate += proc { |_sender, e|
-  pkmn = e[0]
-  if $game_switches[Settings::SHINY_WILD_POKEMON_SWITCH]
-    pkmn.shiny = true
-  end
-}
+EventHandlers.add(:on_wild_pokemon_created, :make_shiny_switch,
+  proc { |pkmn|
+    pkmn.shiny = true if $game_switches[Settings::SHINY_WILD_POKEMON_SWITCH]
+  }
+)
 
-# Used in the random dungeon map.  Makes the levels of all wild Pokémon in that
+# Used in the random dungeon map. Makes the levels of all wild Pokémon in that
 # map depend on the levels of Pokémon in the player's party.
 # This is a simple method, and can/should be modified to account for evolutions
 # and other such details.  Of course, you don't HAVE to use this code.
-Events.onWildPokemonCreate += proc { |_sender, e|
-  pkmn = e[0]
-  if $game_map.map_id == 51
+EventHandlers.add(:on_wild_pokemon_created, :level_depends_on_party,
+  proc { |pkmn|
+    next if $game_map.map_id != 51
     new_level = pbBalancedLevel($player.party) - 4 + rand(5)   # For variety
     new_level = new_level.clamp(1, GameData::GrowthRate.max_level)
     pkmn.level = new_level
     pkmn.calc_stats
     pkmn.reset_moves
-  end
-}
+  }
+)
 
 # This is the basis of a trainer modifier. It works both for trainers loaded
 # when you battle them, and for partner trainers when they are registered.
 # Note that you can only modify a partner trainer's Pokémon, and not the trainer
 # themselves nor their items this way, as those are generated from scratch
 # before each battle.
-#Events.onTrainerPartyLoad += proc { |_sender, trainer|
-#  if trainer   # An NPCTrainer object containing party/items/lose text, etc.
-#    YOUR CODE HERE
-#  end
-#}
+#EventHandlers.trigger(:on_trainer_load, :put_a_name_here,
+#  proc { |trainer|
+#    if trainer   # An NPCTrainer object containing party/items/lose text, etc.
+#      YOUR CODE HERE
+#    end
+#  }
+#)
diff --git a/Data/Scripts/012_Overworld/002_Battle triggering/005_Overworld_RoamingPokemon.rb b/Data/Scripts/012_Overworld/002_Battle triggering/005_Overworld_RoamingPokemon.rb
index ed4ef4943..3b2f26463 100644
--- a/Data/Scripts/012_Overworld/002_Battle triggering/005_Overworld_RoamingPokemon.rb	
+++ b/Data/Scripts/012_Overworld/002_Battle triggering/005_Overworld_RoamingPokemon.rb	
@@ -93,16 +93,17 @@ end
 
 # When the player moves to a new map (with a different name), make all roaming
 # Pokémon roam.
-Events.onMapChange += proc { |_sender, e|
-  oldMapID = e[0]
-  # Get and compare map names
-  mapInfos = pbLoadMapInfos
-  next if mapInfos && oldMapID > 0 && mapInfos[oldMapID] &&
-          mapInfos[oldMapID].name && $game_map.name == mapInfos[oldMapID].name
-  # Make roaming Pokémon roam
-  pbRoamPokemon
-  $PokemonGlobal.roamedAlready = false
-}
+EventHandlers.add(:on_enter_map, :move_roaming_pokemon,
+  proc { |old_map_id|
+    # Get and compare map names
+    mapInfos = pbLoadMapInfos
+    next if mapInfos && old_map_id > 0 && mapInfos[old_map_id] &&
+            mapInfos[old_map_id].name && $game_map.name == mapInfos[old_map_id].name
+    # Make roaming Pokémon roam
+    pbRoamPokemon
+    $PokemonGlobal.roamedAlready = false
+  }
+)
 
 
 
@@ -135,64 +136,69 @@ def pbRoamingMethodAllowed(roamer_method)
   return false
 end
 
-EncounterModifier.register(proc { |encounter|
-  $game_temp.roamer_index_for_encounter = nil
-  next nil if !encounter
-  # Give the regular encounter if encountering a roaming Pokémon isn't possible
-  next encounter if $PokemonGlobal.roamedAlready
-  next encounter if $PokemonGlobal.partner
-  next encounter if $game_temp.poke_radar_data
-  next encounter if rand(100) < 75   # 25% chance of encountering a roaming Pokémon
-  # Look at each roaming Pokémon in turn and decide whether it's possible to
-  # encounter it
-  currentRegion = pbGetCurrentRegion
-  currentMapName = $game_map.name
-  possible_roamers = []
-  Settings::ROAMING_SPECIES.each_with_index do |data, i|
-    # data = [species, level, Game Switch, roamer method, battle BGM, area maps hash]
-    next if !GameData::Species.exists?(data[0])
-    next if data[2] > 0 && !$game_switches[data[2]]   # Isn't roaming
-    next if $PokemonGlobal.roamPokemon[i] == true   # Roaming Pokémon has been caught
-    # Get the roamer's current map
-    roamerMap = $PokemonGlobal.roamPosition[i]
-    if !roamerMap
-      mapIDs = pbRoamingAreas(i).keys   # Hash of area patrolled by the roaming Pokémon
-      next if !mapIDs || mapIDs.length == 0   # No roaming area defined somehow
-      roamerMap = mapIDs[rand(mapIDs.length)]
-      $PokemonGlobal.roamPosition[i] = roamerMap
+EventHandlers.add(:on_wild_species_chosen, :roaming_pokemon,
+  proc { |encounter|
+    $game_temp.roamer_index_for_encounter = nil
+    next if !encounter
+    # Give the regular encounter if encountering a roaming Pokémon isn't possible
+    next if $PokemonGlobal.roamedAlready
+    next if $PokemonGlobal.partner
+    next if $game_temp.poke_radar_data
+    next if rand(100) < 75   # 25% chance of encountering a roaming Pokémon
+    # Look at each roaming Pokémon in turn and decide whether it's possible to
+    # encounter it
+    currentRegion = pbGetCurrentRegion
+    currentMapName = $game_map.name
+    possible_roamers = []
+    Settings::ROAMING_SPECIES.each_with_index do |data, i|
+      # data = [species, level, Game Switch, roamer method, battle BGM, area maps hash]
+      next if !GameData::Species.exists?(data[0])
+      next if data[2] > 0 && !$game_switches[data[2]]   # Isn't roaming
+      next if $PokemonGlobal.roamPokemon[i] == true   # Roaming Pokémon has been caught
+      # Get the roamer's current map
+      roamerMap = $PokemonGlobal.roamPosition[i]
+      if !roamerMap
+        mapIDs = pbRoamingAreas(i).keys   # Hash of area patrolled by the roaming Pokémon
+        next if !mapIDs || mapIDs.length == 0   # No roaming area defined somehow
+        roamerMap = mapIDs[rand(mapIDs.length)]
+        $PokemonGlobal.roamPosition[i] = roamerMap
+      end
+      # If roamer isn't on the current map, check if it's on a map with the same
+      # name and in the same region
+      if roamerMap != $game_map.map_id
+        map_metadata = GameData::MapMetadata.try_get(roamerMap)
+        next if !map_metadata || !map_metadata.town_map_position ||
+                map_metadata.town_map_position[0] != currentRegion
+        next if pbGetMapNameFromId(roamerMap) != currentMapName
+      end
+      # Check whether the roamer's roamer method is currently possible
+      next if !pbRoamingMethodAllowed(data[3])
+      # Add this roaming Pokémon to the list of possible roaming Pokémon to encounter
+      possible_roamers.push([i, data[0], data[1], data[4]])   # [i, species, level, BGM]
     end
-    # If roamer isn't on the current map, check if it's on a map with the same
-    # name and in the same region
-    if roamerMap != $game_map.map_id
-      map_metadata = GameData::MapMetadata.try_get(roamerMap)
-      next if !map_metadata || !map_metadata.town_map_position ||
-              map_metadata.town_map_position[0] != currentRegion
-      next if pbGetMapNameFromId(roamerMap) != currentMapName
-    end
-    # Check whether the roamer's roamer method is currently possible
-    next if !pbRoamingMethodAllowed(data[3])
-    # Add this roaming Pokémon to the list of possible roaming Pokémon to encounter
-    possible_roamers.push([i, data[0], data[1], data[4]])   # [i, species, level, BGM]
-  end
-  # No encounterable roaming Pokémon were found, just have the regular encounter
-  next encounter if possible_roamers.length == 0
-  # Pick a roaming Pokémon to encounter out of those available
-  roamer = possible_roamers[rand(possible_roamers.length)]
-  $PokemonGlobal.roamEncounter = roamer
-  $game_temp.roamer_index_for_encounter = roamer[0]
-  $PokemonGlobal.nextBattleBGM = roamer[3] if roamer[3] && !roamer[3].empty?
-  $game_temp.force_single_battle = true
-  next [roamer[1], roamer[2]]   # Species, level
-})
+    # No encounterable roaming Pokémon were found, just have the regular encounter
+    next if possible_roamers.length == 0
+    # Pick a roaming Pokémon to encounter out of those available
+    roamer = possible_roamers.sample
+    $PokemonGlobal.roamEncounter = roamer
+    $game_temp.roamer_index_for_encounter = roamer[0]
+    $PokemonGlobal.nextBattleBGM = roamer[3] if roamer[3] && !roamer[3].empty?
+    $game_temp.force_single_battle = true
+    encounter[0] = roamer[1]   # Species
+    encounter[1] = roamer[2]   # Level
+  }
+)
 
-Events.onWildBattleOverride += proc { |_sender, e|
-  species = e[0]
-  level   = e[1]
-  handled = e[2]
-  next if handled[0] != nil
-  next if !$PokemonGlobal.roamEncounter || $game_temp.roamer_index_for_encounter.nil?
-  handled[0] = pbRoamingPokemonBattle(species, level)
-}
+EventHandlers.add(:on_calling_wild_battle, :roaming_pokemon,
+  proc { |species, level, handled|
+    # handled is an array: [nil]. If [true] or [false], the battle has already
+    # been overridden (the boolean is its outcome), so don't do anything that
+    # would override it again
+    next if !handled[0].nil?
+    next if !$PokemonGlobal.roamEncounter || $game_temp.roamer_index_for_encounter.nil?
+    handled[0] = pbRoamingPokemonBattle(species, level)
+  }
+)
 
 def pbRoamingPokemonBattle(species, level)
   # Get the roaming Pokémon to encounter; generate it based on the species and
@@ -214,12 +220,9 @@ def pbRoamingPokemonBattle(species, level)
   end
   $PokemonGlobal.roamEncounter = nil
   $PokemonGlobal.roamedAlready = true
+  $game_temp.roamer_index_for_encounter = nil
   # Used by the Poké Radar to update/break the chain
-  Events.onWildBattleEnd.trigger(nil, species, level, decision)
+  EventHandlers.trigger(:on_wild_battle_end, species, level, decision)
   # Return false if the player lost or drew the battle, and true if any other result
   return (decision != 2 && decision != 5)
 end
-
-EncounterModifier.registerEncounterEnd(proc {
-  $game_temp.roamer_index_for_encounter = nil
-})
diff --git a/Data/Scripts/012_Overworld/004_Overworld_FieldMoves.rb b/Data/Scripts/012_Overworld/004_Overworld_FieldMoves.rb
index bda89da78..6b2128b98 100644
--- a/Data/Scripts/012_Overworld/004_Overworld_FieldMoves.rb
+++ b/Data/Scripts/012_Overworld/004_Overworld_FieldMoves.rb
@@ -49,7 +49,7 @@ end
 
 # Unused
 def pbHiddenMoveEvent
-  Events.onAction.trigger(nil)
+  EventHandlers.trigger(:on_player_interact)
 end
 
 def pbCheckHiddenMoveBadge(badge = -1, showmsg = true)
@@ -383,22 +383,24 @@ def pbTransferUnderwater(mapid, x, y, direction = $game_player.direction)
   }
 end
 
-Events.onAction += proc { |_sender, _e|
-  if $PokemonGlobal.diving
-    surface_map_id = nil
-    GameData::MapMetadata.each do |map_data|
-      next if !map_data.dive_map_id || map_data.dive_map_id != $game_map.map_id
-      surface_map_id = map_data.id
-      break
+EventHandlers.add(:on_player_interact, :diving,
+  proc {
+    if $PokemonGlobal.diving
+      surface_map_id = nil
+      GameData::MapMetadata.each do |map_data|
+        next if !map_data.dive_map_id || map_data.dive_map_id != $game_map.map_id
+        surface_map_id = map_data.id
+        break
+      end
+      if surface_map_id &&
+         $map_factory.getTerrainTag(surface_map_id, $game_player.x, $game_player.y).can_dive
+        pbSurfacing
+      end
+    elsif $game_player.terrain_tag.can_dive
+      pbDive
     end
-    if surface_map_id &&
-       $map_factory.getTerrainTag(surface_map_id, $game_player.x, $game_player.y).can_dive
-      pbSurfacing
-    end
-  elsif $game_player.terrain_tag.can_dive
-    pbDive
-  end
-}
+  }
+)
 
 HiddenMoveHandlers::CanUseMove.add(:DIVE, proc { |move, pkmn, showmsg|
   next false if !pbCheckHiddenMoveBadge(Settings::BADGE_FOR_DIVE, showmsg)
@@ -703,10 +705,12 @@ def pbStrength
   return false
 end
 
-Events.onAction += proc { |_sender, _e|
-  facingEvent = $game_player.pbFacingEvent
-  pbStrength if facingEvent && facingEvent.name[/strengthboulder/i]
-}
+EventHandlers.add(:on_player_interact, :strength_event,
+  proc {
+    facingEvent = $game_player.pbFacingEvent
+    pbStrength if facingEvent && facingEvent.name[/strengthboulder/i]
+  }
+)
 
 HiddenMoveHandlers::CanUseMove.add(:STRENGTH, proc { |move, pkmn, showmsg|
   next false if !pbCheckHiddenMoveBadge(Settings::BADGE_FOR_STRENGTH, showmsg)
@@ -796,13 +800,15 @@ def pbTransferSurfing(mapid, xcoord, ycoord, direction = $game_player.direction)
   }
 end
 
-Events.onAction += proc { |_sender, _e|
-  next if $PokemonGlobal.surfing
-  next if $game_map.metadata&.always_bicycle
-  next if !$game_player.pbFacingTerrainTag.can_surf_freely
-  next if !$game_map.passable?($game_player.x, $game_player.y, $game_player.direction, $game_player)
-  pbSurf
-}
+EventHandlers.add(:on_player_interact, :start_surfing,
+  proc {
+    next if $PokemonGlobal.surfing
+    next if $game_map.metadata&.always_bicycle
+    next if !$game_player.pbFacingTerrainTag.can_surf_freely
+    next if !$game_map.passable?($game_player.x, $game_player.y, $game_player.direction, $game_player)
+    pbSurf
+  }
+)
 
 HiddenMoveHandlers::CanUseMove.add(:SURF, proc { |move, pkmn, showmsg|
   next false if !pbCheckHiddenMoveBadge(Settings::BADGE_FOR_SURF, showmsg)
@@ -1001,14 +1007,16 @@ def pbWaterfall
   return false
 end
 
-Events.onAction += proc { |_sender, _e|
-  terrain = $game_player.pbFacingTerrainTag
-  if terrain.waterfall
-    pbWaterfall
-  elsif terrain.waterfall_crest
-    pbMessage(_INTL("A wall of water is crashing down with a mighty roar."))
-  end
-}
+EventHandlers.add(:on_player_interact, :waterfall,
+  proc {
+    terrain = $game_player.pbFacingTerrainTag
+    if terrain.waterfall
+      pbWaterfall
+    elsif terrain.waterfall_crest
+      pbMessage(_INTL("A wall of water is crashing down with a mighty roar."))
+    end
+  }
+)
 
 HiddenMoveHandlers::CanUseMove.add(:WATERFALL, proc { |move, pkmn, showmsg|
   next false if !pbCheckHiddenMoveBadge(Settings::BADGE_FOR_WATERFALL, showmsg)
diff --git a/Data/Scripts/012_Overworld/006_Overworld_BerryPlants.rb b/Data/Scripts/012_Overworld/006_Overworld_BerryPlants.rb
index 1b692e018..0e17f8c2d 100644
--- a/Data/Scripts/012_Overworld/006_Overworld_BerryPlants.rb
+++ b/Data/Scripts/012_Overworld/006_Overworld_BerryPlants.rb
@@ -290,16 +290,16 @@ end
 #===============================================================================
 #
 #===============================================================================
-Events.onSpritesetCreate += proc { |_sender, e|
-  spriteset = e[0]
-  viewport  = e[1]
-  map = spriteset.map
-  map.events.each do |event|
-    next if !event[1].name[/berryplant/i]
-    spriteset.addUserSprite(BerryPlantMoistureSprite.new(event[1], map, viewport))
-    spriteset.addUserSprite(BerryPlantSprite.new(event[1], map, viewport))
-  end
-}
+EventHandlers.add(:on_new_spriteset_map, :add_berry_plant_graphics,
+  proc { |spriteset, viewport|
+    map = spriteset.map
+    map.events.each do |event|
+      next if !event[1].name[/berryplant/i]
+      spriteset.addUserSprite(BerryPlantMoistureSprite.new(event[1], map, viewport))
+      spriteset.addUserSprite(BerryPlantSprite.new(event[1], map, viewport))
+    end
+  }
+)
 
 #===============================================================================
 #
diff --git a/Data/Scripts/012_Overworld/007_Overworld_DayCare.rb b/Data/Scripts/012_Overworld/007_Overworld_DayCare.rb
index 44f9c5f99..b10188289 100644
--- a/Data/Scripts/012_Overworld/007_Overworld_DayCare.rb
+++ b/Data/Scripts/012_Overworld/007_Overworld_DayCare.rb
@@ -557,9 +557,11 @@ end
 # With each step taken, add Exp to Pokémon in the Day Care and try to generate
 # an egg.
 #===============================================================================
-Events.onStepTaken += proc { |_sender, _e|
-  $PokemonGlobal.day_care.update_on_step_taken
-}
+EventHandlers.add(:on_player_step_taken, :update_day_care,
+  proc {
+    $PokemonGlobal.day_care.update_on_step_taken
+  }
+)
 
 #===============================================================================
 # Deprecated methods
diff --git a/Data/Scripts/012_Overworld/008_Overworld_RandomDungeons.rb b/Data/Scripts/012_Overworld/008_Overworld_RandomDungeons.rb
index dcbfd4088..b68e7bfe7 100644
--- a/Data/Scripts/012_Overworld/008_Overworld_RandomDungeons.rb
+++ b/Data/Scripts/012_Overworld/008_Overworld_RandomDungeons.rb
@@ -643,27 +643,27 @@ module RandomDungeonGenerator
   end
 end
 
-Events.onMapCreate += proc { |_sender, e|
-  mapID = e[0]
-  map   = e[1]
-  next if !GameData::MapMetadata.try_get(mapID)&.random_dungeon
-  # this map is a randomly generated dungeon
-  dungeon = RandomDungeonGenerator::Dungeon.new(map.width, map.height)
-  dungeon.generate
-  dungeon.generateMapInPlace(map)
-  roomtiles = []
-  # Reposition events
-  map.events.values.each do |event|
+EventHandlers.add(:on_game_map_setup, :random_dungeon,
+  proc { |map_id, map, _tileset_data|
+    next if !GameData::MapMetadata.try_get(map_id)&.random_dungeon
+    # this map is a randomly generated dungeon
+    dungeon = RandomDungeonGenerator::Dungeon.new(map.width, map.height)
+    dungeon.generate
+    dungeon.generateMapInPlace(map)
+    roomtiles = []
+    # Reposition events
+    map.events.values.each do |event|
+      tile = RandomDungeonGenerator.pbRandomRoomTile(dungeon, roomtiles)
+      if tile
+        event.x = tile[0]
+        event.y = tile[1]
+      end
+    end
+    # Override transfer X and Y
     tile = RandomDungeonGenerator.pbRandomRoomTile(dungeon, roomtiles)
     if tile
-      event.x = tile[0]
-      event.y = tile[1]
+      $game_temp.player_new_x = tile[0]
+      $game_temp.player_new_y = tile[1]
     end
-  end
-  # Override transfer X and Y
-  tile = RandomDungeonGenerator.pbRandomRoomTile(dungeon, roomtiles)
-  if tile
-    $game_temp.player_new_x = tile[0]
-    $game_temp.player_new_y = tile[1]
-  end
-}
+  }
+)
diff --git a/Data/Scripts/013_Items/002_Item_Effects.rb b/Data/Scripts/013_Items/002_Item_Effects.rb
index 563c92ea7..94635e7d2 100644
--- a/Data/Scripts/013_Items/002_Item_Effects.rb
+++ b/Data/Scripts/013_Items/002_Item_Effects.rb
@@ -134,25 +134,27 @@ ItemHandlers::UseInField.add(:MAXREPEL, proc { |item|
   next pbRepel(item, 250)
 })
 
-Events.onStepTaken += proc {
-  next if $PokemonGlobal.repel <= 0 || $game_player.terrain_tag.ice   # Shouldn't count down if on ice
-  $PokemonGlobal.repel -= 1
-  next if $PokemonGlobal.repel > 0
-  repels = []
-  GameData::Item.each { |itm| repels.push(itm.id) if itm.has_flag?("Repel") }
-  if repels.none? { |item| $bag.has?(item) }
-    pbMessage(_INTL("The repellent's effect wore off!"))
-    next
-  end
-  next if !pbConfirmMessage(_INTL("The repellent's effect wore off! Would you like to use another one?"))
-  ret = nil
-  pbFadeOutIn {
-    scene = PokemonBag_Scene.new
-    screen = PokemonBagScreen.new(scene, $bag)
-    ret = screen.pbChooseItemScreen(proc { |item| repels.include?(item) })
+EventHandlers.add(:on_player_step_taken, :repel_counter,
+  proc {
+    next if $PokemonGlobal.repel <= 0 || $game_player.terrain_tag.ice   # Shouldn't count down if on ice
+    $PokemonGlobal.repel -= 1
+    next if $PokemonGlobal.repel > 0
+    repels = []
+    GameData::Item.each { |itm| repels.push(itm.id) if itm.has_flag?("Repel") }
+    if repels.none? { |item| $bag.has?(item) }
+      pbMessage(_INTL("The repellent's effect wore off!"))
+      next
+    end
+    next if !pbConfirmMessage(_INTL("The repellent's effect wore off! Would you like to use another one?"))
+    ret = nil
+    pbFadeOutIn {
+      scene = PokemonBag_Scene.new
+      screen = PokemonBagScreen.new(scene, $bag)
+      ret = screen.pbChooseItemScreen(proc { |item| repels.include?(item) })
+    }
+    pbUseItem($bag, ret) if ret
   }
-  pbUseItem($bag, ret) if ret
-}
+)
 
 ItemHandlers::UseInField.add(:BLACKFLUTE, proc { |item|
   pbUseItemMessage(item)
diff --git a/Data/Scripts/013_Items/004_Item_Phone.rb b/Data/Scripts/013_Items/004_Item_Phone.rb
index b949c9450..4b4c26e88 100644
--- a/Data/Scripts/013_Items/004_Item_Phone.rb
+++ b/Data/Scripts/013_Items/004_Item_Phone.rb
@@ -131,47 +131,48 @@ end
 #===============================================================================
 # Phone-related counters
 #===============================================================================
-Events.onMapUpdate += proc { |_sender, _e|
-  next if !$player || !$player.has_pokegear
-  # Reset time to next phone call if necessary
-  if !$PokemonGlobal.phoneTime || $PokemonGlobal.phoneTime <= 0
-    $PokemonGlobal.phoneTime = 20 * 60 * Graphics.frame_rate
-    $PokemonGlobal.phoneTime += rand(20 * 60 * Graphics.frame_rate)
-  end
-  # Don't count down various phone times if other things are happening
-  $PokemonGlobal.phoneNumbers = [] if !$PokemonGlobal.phoneNumbers
-  next if $game_temp.in_menu || $game_temp.in_battle || $game_temp.message_window_showing
-  next if $game_player.move_route_forcing || pbMapInterpreterRunning?
-  # Count down time to next phone call
-  $PokemonGlobal.phoneTime -= 1
-  # Count down time to next can-battle for each trainer contact
-  if $PokemonGlobal.phoneTime % Graphics.frame_rate == 0   # Every second
-    $PokemonGlobal.phoneNumbers.each do |num|
-      next if !num[0] || num.length != 8   # if not visible or not a trainer
-      # Reset time to next can-battle if necessary
-      if num[4] == 0
-        num[3] = rand(20...40) * 60   # 20-40 minutes
-        num[4] = 1
-      end
-      # Count down time to next can-battle
-      num[3] -= 1
-      # Ready to battle
-      if num[3] <= 0 && num[4] == 1
-        num[4] = 2   # set ready-to-battle flag
-        pbSetReadyToBattle(num)
+EventHandlers.add(:on_frame_update, :phone_call_counter,
+  proc {
+    next if !$player&.has_pokegear
+    # Reset time to next phone call if necessary
+    if !$PokemonGlobal.phoneTime || $PokemonGlobal.phoneTime <= 0
+      $PokemonGlobal.phoneTime = rand(20...40) * 60 * Graphics.frame_rate
+    end
+    # Don't count down various phone times if other things are happening
+    $PokemonGlobal.phoneNumbers = [] if !$PokemonGlobal.phoneNumbers
+    next if $game_temp.in_menu || $game_temp.in_battle || $game_temp.message_window_showing
+    next if $game_player.move_route_forcing || pbMapInterpreterRunning?
+    # Count down time to next phone call
+    $PokemonGlobal.phoneTime -= 1
+    # Count down time to next can-battle for each trainer contact
+    if $PokemonGlobal.phoneTime % Graphics.frame_rate == 0   # Every second
+      $PokemonGlobal.phoneNumbers.each do |num|
+        next if !num[0] || num.length != 8   # if not visible or not a trainer
+        # Reset time to next can-battle if necessary
+        if num[4] == 0
+          num[3] = rand(20...40) * 60   # 20-40 minutes
+          num[4] = 1
+        end
+        # Count down time to next can-battle
+        num[3] -= 1
+        # Ready to battle
+        if num[3] <= 0 && num[4] == 1
+          num[4] = 2   # set ready-to-battle flag
+          pbSetReadyToBattle(num)
+        end
       end
     end
-  end
-  # Time for a random phone call; generate one
-  if $PokemonGlobal.phoneTime <= 0
-    # find all trainer phone numbers
-    phonenum = pbRandomPhoneTrainer
-    if phonenum
-      call = pbPhoneGenerateCall(phonenum)
-      pbPhoneCall(call, phonenum)
+    # Time for a random phone call; generate one
+    if $PokemonGlobal.phoneTime <= 0
+      # find all trainer phone numbers
+      phonenum = pbRandomPhoneTrainer
+      if phonenum
+        call = pbPhoneGenerateCall(phonenum)
+        pbPhoneCall(call, phonenum)
+      end
     end
-  end
-}
+  }
+)
 
 #===============================================================================
 # Player calls a contact
diff --git a/Data/Scripts/013_Items/005_Item_PokeRadar.rb b/Data/Scripts/013_Items/005_Item_PokeRadar.rb
index 0cb9fc353..0da167dd4 100644
--- a/Data/Scripts/013_Items/005_Item_PokeRadar.rb
+++ b/Data/Scripts/013_Items/005_Item_PokeRadar.rb
@@ -151,90 +151,102 @@ end
 ################################################################################
 # Event handlers
 ################################################################################
-EncounterModifier.register(proc { |encounter|
-  if GameData::EncounterType.get($game_temp.encounter_type).type != :land ||
-     $PokemonGlobal.bicycle || $PokemonGlobal.partner
-    pbPokeRadarCancel
-    next encounter
-  end
-  ring = pbPokeRadarGetShakingGrass
-  if ring >= 0   # Encounter triggered by stepping into rustling grass
-    # Get rarity of shaking grass
-    rarity = 0   # 0 = rustle, 1 = vigorous rustle, 2 = shiny rustle
-    $game_temp.poke_radar_data[3].each { |g| rarity = g[3] if g[2] == ring }
-    if $game_temp.poke_radar_data[2] > 0   # Chain count, i.e. is chaining
-      if rarity == 2 ||
-         rand(100) < 58 + (ring * 10) + ([$game_temp.poke_radar_data[2], 40].min / 4) + ($game_temp.poke_radar_data[4] ? 10 : 0)
-        # Continue the chain
-        encounter = [$game_temp.poke_radar_data[0], $game_temp.poke_radar_data[1]]
-        $game_temp.force_single_battle = true
-      else
-        # Break the chain, force an encounter with a different species
-        100.times do
-          break if encounter && encounter[0] != $game_temp.poke_radar_data[0]
-          encounter = $PokemonEncounters.choose_wild_pokemon($PokemonEncounters.encounter_type)
-        end
-        if encounter[0] == $game_temp.poke_radar_data[0] && encounter[1] == $game_temp.poke_radar_data[1]
-          # Chain couldn't be broken somehow; continue it after all
+EventHandlers.add(:on_wild_species_chosen, :poke_radar_chain,
+  proc { |encounter|
+    if GameData::EncounterType.get($game_temp.encounter_type).type != :land ||
+       $PokemonGlobal.bicycle || $PokemonGlobal.partner
+      pbPokeRadarCancel
+      next
+    end
+    ring = pbPokeRadarGetShakingGrass
+    if ring >= 0   # Encounter triggered by stepping into rustling grass
+      # Get rarity of shaking grass
+      rarity = 0   # 0 = rustle, 1 = vigorous rustle, 2 = shiny rustle
+      $game_temp.poke_radar_data[3].each { |g| rarity = g[3] if g[2] == ring }
+      if $game_temp.poke_radar_data[2] > 0   # Chain count, i.e. is chaining
+        chain_chance = 58 + (ring * 10)
+        chain_chance += [$game_temp.poke_radar_data[2], 40].min / 4   # Chain length
+        chain_chance += 10 if $game_temp.poke_radar_data[4]   # Previous in chain was caught
+        if rarity == 2 || rand(100) < chain_chance
+          # Continue the chain
+          encounter[0] = $game_temp.poke_radar_data[0]   # Species
+          encounter[1] = $game_temp.poke_radar_data[1]   # Level
           $game_temp.force_single_battle = true
         else
-          pbPokeRadarCancel
+          # Break the chain, force an encounter with a different species
+          100.times do
+            break if encounter && encounter[0] != $game_temp.poke_radar_data[0]
+            new_encounter = $PokemonEncounters.choose_wild_pokemon($PokemonEncounters.encounter_type)
+            encounter[0] = new_encounter[0]
+            encounter[1] = new_encounter[1]
+          end
+          if encounter[0] == $game_temp.poke_radar_data[0] && encounter[1] == $game_temp.poke_radar_data[1]
+            # Chain couldn't be broken somehow; continue it after all
+            $game_temp.force_single_battle = true
+          else
+            pbPokeRadarCancel
+          end
         end
+      else   # Not chaining; will start one
+        # Force random wild encounter, vigorous shaking means rarer species
+        new_encounter = pbPokeRadarGetEncounter(rarity)
+        encounter[0] = new_encounter[0]
+        encounter[1] = new_encounter[1]
+        $game_temp.force_single_battle = true
       end
-    else   # Not chaining; will start one
-      # Force random wild encounter, vigorous shaking means rarer species
-      encounter = pbPokeRadarGetEncounter(rarity)
-      $game_temp.force_single_battle = true
+    elsif encounter   # Encounter triggered by stepping in non-rustling grass
+      pbPokeRadarCancel
     end
-  elsif encounter   # Encounter triggered by stepping in non-rustling grass
+  }
+)
+
+EventHandlers.add(:on_wild_pokemon_created, :poke_radar_shiny,
+  proc { |pkmn|
+    next if !$game_temp.poke_radar_data
+    grasses = $game_temp.poke_radar_data[3]
+    next if !grasses
+    grasses.each do |grass|
+      next if $game_player.x != grass[0] || $game_player.y != grass[1]
+      pkmn.shiny = true if grass[3] == 2
+      break
+    end
+  }
+)
+
+EventHandlers.add(:on_wild_battle_end, :poke_radar_continue_chain,
+  proc { |species, level, decision|
+    if $game_temp.poke_radar_data && [1, 4].include?(decision)   # Defeated/caught
+      $game_temp.poke_radar_data[0] = species
+      $game_temp.poke_radar_data[1] = level
+      $game_temp.poke_radar_data[2] += 1
+      $stats.poke_radar_longest_chain = [$game_temp.poke_radar_data[2], $stats.poke_radar_longest_chain].max
+      # Catching makes the next Radar encounter more likely to continue the chain
+      $game_temp.poke_radar_data[4] = (decision == 4)
+      pbPokeRadarHighlightGrass(false)
+    else
+      pbPokeRadarCancel
+    end
+  }
+)
+
+EventHandlers.add(:on_player_step_taken, :poke_radar,
+  proc {
+    if $PokemonGlobal.pokeradarBattery && $PokemonGlobal.pokeradarBattery > 0 &&
+       !$game_temp.poke_radar_data
+      $PokemonGlobal.pokeradarBattery -= 1
+    end
+    terrain = $game_map.terrain_tag($game_player.x, $game_player.y)
+    if !terrain.land_wild_encounters || !terrain.shows_grass_rustle
+      pbPokeRadarCancel
+    end
+  }
+)
+
+EventHandlers.add(:on_enter_map, :cancel_poke_radar,
+  proc { |_old_map_id|
     pbPokeRadarCancel
-  end
-  next encounter
-})
-
-Events.onWildPokemonCreate += proc { |_sender, e|
-  pokemon = e[0]
-  next if !$game_temp.poke_radar_data
-  grasses = $game_temp.poke_radar_data[3]
-  next if !grasses
-  grasses.each do |grass|
-    next if $game_player.x != grass[0] || $game_player.y != grass[1]
-    pokemon.shiny = true if grass[3] == 2
-    break
-  end
-}
-
-Events.onWildBattleEnd += proc { |_sender, e|
-  species  = e[0]
-  level    = e[1]
-  decision = e[2]
-  if $game_temp.poke_radar_data && [1, 4].include?(decision)   # Defeated/caught
-    $game_temp.poke_radar_data[0] = species
-    $game_temp.poke_radar_data[1] = level
-    $game_temp.poke_radar_data[2] += 1
-    $stats.poke_radar_longest_chain = [$game_temp.poke_radar_data[2], $stats.poke_radar_longest_chain].max
-    # Catching makes the next Radar encounter more likely to continue the chain
-    $game_temp.poke_radar_data[4] = (decision == 4)
-    pbPokeRadarHighlightGrass(false)
-  else
-    pbPokeRadarCancel
-  end
-}
-
-Events.onStepTaken += proc { |_sender, _e|
-  if $PokemonGlobal.pokeradarBattery && $PokemonGlobal.pokeradarBattery > 0 &&
-     !$game_temp.poke_radar_data
-    $PokemonGlobal.pokeradarBattery -= 1
-  end
-  terrain = $game_map.terrain_tag($game_player.x, $game_player.y)
-  if !terrain.land_wild_encounters || !terrain.shows_grass_rustle
-    pbPokeRadarCancel
-  end
-}
-
-Events.onMapChange += proc { |_sender, _e|
-  pbPokeRadarCancel
-}
+  }
+)
 
 ################################################################################
 # Item handlers
diff --git a/Data/Scripts/014_Pokemon/001_Pokemon-related/002_ShadowPokemon_Other.rb b/Data/Scripts/014_Pokemon/001_Pokemon-related/002_ShadowPokemon_Other.rb
index f92ffc558..a6adb1480 100644
--- a/Data/Scripts/014_Pokemon/001_Pokemon-related/002_ShadowPokemon_Other.rb
+++ b/Data/Scripts/014_Pokemon/001_Pokemon-related/002_ShadowPokemon_Other.rb
@@ -396,39 +396,43 @@ end
 
 # Record current heart gauges of Pokémon in party, to see if they drop to zero
 # during battle and need to say they're ready to be purified afterwards
-Events.onStartBattle += proc { |_sender|
-  $game_temp.party_heart_gauges_before_battle = []
-  $player.party.each_with_index do |pkmn, i|
-    $game_temp.party_heart_gauges_before_battle[i] = pkmn.heart_gauge
-  end
-}
-
-Events.onEndBattle += proc { |_sender, _e|
-  $game_temp.party_heart_gauges_before_battle.each_with_index do |value, i|
-    pkmn = $player.party[i]
-    next if !pkmn || !value || value == 0
-    pkmn.check_ready_to_purify if pkmn.heart_gauge == 0
-  end
-}
-
-Events.onStepTaken += proc {
-  $player.able_party.each do |pkmn|
-    next if pkmn.heart_gauge == 0
-    pkmn.heart_gauge_step_counter = 0 if !pkmn.heart_gauge_step_counter
-    pkmn.heart_gauge_step_counter += 1
-    if pkmn.heart_gauge_step_counter >= 256
-      old_stage = pkmn.heartStage
-      pkmn.change_heart_gauge("walking")
-      new_stage = pkmn.heartStage
-      if new_stage == 0
-        pkmn.check_ready_to_purify
-      elsif new_stage != old_stage
-        pkmn.update_shadow_moves
-      end
-      pkmn.heart_gauge_step_counter = 0
+EventHandlers.add(:on_start_battle, :record_party_heart_gauges,
+  proc {
+    $game_temp.party_heart_gauges_before_battle = []
+    $player.party.each_with_index do |pkmn, i|
+      $game_temp.party_heart_gauges_before_battle[i] = pkmn.heart_gauge
     end
-  end
-  if ($PokemonGlobal.purifyChamber rescue nil)
-    $PokemonGlobal.purifyChamber.update
-  end
-}
+  }
+)
+
+EventHandlers.add(:on_end_battle, :check_ready_to_purify,
+  proc { |_decision, _canLose|
+    $game_temp.party_heart_gauges_before_battle.each_with_index do |value, i|
+      pkmn = $player.party[i]
+      next if !pkmn || !value || value == 0
+      pkmn.check_ready_to_purify if pkmn.heart_gauge == 0
+    end
+  }
+)
+
+EventHandlers.add(:on_player_step_taken, :lower_heart_gauges,
+  proc {
+    $player.able_party.each do |pkmn|
+      next if pkmn.heart_gauge == 0
+      pkmn.heart_gauge_step_counter = 0 if !pkmn.heart_gauge_step_counter
+      pkmn.heart_gauge_step_counter += 1
+      if pkmn.heart_gauge_step_counter >= 256
+        old_stage = pkmn.heartStage
+        pkmn.change_heart_gauge("walking")
+        new_stage = pkmn.heartStage
+        if new_stage == 0
+          pkmn.check_ready_to_purify
+        elsif new_stage != old_stage
+          pkmn.update_shadow_moves
+        end
+        pkmn.heart_gauge_step_counter = 0
+      end
+    end
+    $PokemonGlobal.purifyChamber&.update
+  }
+)
diff --git a/Data/Scripts/016_UI/001_Non-interactive UI/003_UI_EggHatching.rb b/Data/Scripts/016_UI/001_Non-interactive UI/003_UI_EggHatching.rb
index cbbede2e5..68eef5dec 100644
--- a/Data/Scripts/016_UI/001_Non-interactive UI/003_UI_EggHatching.rb	
+++ b/Data/Scripts/016_UI/001_Non-interactive UI/003_UI_EggHatching.rb	
@@ -217,18 +217,20 @@ def pbHatch(pokemon)
   end
 end
 
-Events.onStepTaken += proc { |_sender, _e|
-  $player.party.each do |egg|
-    next if egg.steps_to_hatch <= 0
-    egg.steps_to_hatch -= 1
-    $player.pokemon_party.each do |pkmn|
-      next if !pkmn.ability&.has_flag?("FasterEggHatching")
+EventHandlers.add(:on_player_step_taken, :hatch_eggs,
+  proc {
+    $player.party.each do |egg|
+      next if egg.steps_to_hatch <= 0
       egg.steps_to_hatch -= 1
-      break
+      $player.pokemon_party.each do |pkmn|
+        next if !pkmn.ability&.has_flag?("FasterEggHatching")
+        egg.steps_to_hatch -= 1
+        break
+      end
+      if egg.steps_to_hatch <= 0
+        egg.steps_to_hatch = 0
+        pbHatch(egg)
+      end
     end
-    if egg.steps_to_hatch <= 0
-      egg.steps_to_hatch = 0
-      pbHatch(egg)
-    end
-  end
-}
+  }
+)
diff --git a/Data/Scripts/018_Alternate battle modes/001_SafariZone.rb b/Data/Scripts/018_Alternate battle modes/001_SafariZone.rb
index 3e7f35a7f..058f67c2c 100644
--- a/Data/Scripts/018_Alternate battle modes/001_SafariZone.rb	
+++ b/Data/Scripts/018_Alternate battle modes/001_SafariZone.rb	
@@ -55,9 +55,11 @@ end
 
 
 
-Events.onMapChange += proc { |_sender, *args|
-  pbSafariState.pbEnd if !pbInSafari?
-}
+EventHandlers.add(:on_enter_map, :end_safari_game,
+  proc { |_old_map_id|
+    pbSafariState.pbEnd if !pbInSafari?
+  }
+)
 
 def pbInSafari?
   if pbSafariState.inProgress?
@@ -75,29 +77,32 @@ def pbSafariState
   return $PokemonGlobal.safariState
 end
 
-Events.onStepTakenTransferPossible += proc { |_sender, e|
-  handled = e[0]
-  next if handled[0]
-  if pbInSafari? && pbSafariState.decision == 0 && Settings::SAFARI_STEPS > 0
+EventHandlers.add(:on_player_step_taken_can_transfer, :safari_game_counter,
+  proc { |handled|
+    # handled is an array: [nil]. If [true], a message has already been shown
+    # because of this step, so don't do anything that might show another one
+    next if handled[0]
+    next if Settings::SAFARI_STEPS == 0 || !pbInSafari? || pbSafariState.decision != 0
     pbSafariState.steps -= 1
-    if pbSafariState.steps <= 0
-      pbMessage(_INTL("PA:  Ding-dong!\1"))
-      pbMessage(_INTL("PA:  Your safari game is over!"))
-      pbSafariState.decision = 1
-      pbSafariState.pbGoToStart
-      handled[0] = true
-    end
-  end
-}
+    next if pbSafariState.steps > 0
+    pbMessage(_INTL("PA: Ding-dong!\1"))
+    pbMessage(_INTL("PA: Your safari game is over!"))
+    pbSafariState.decision = 1
+    pbSafariState.pbGoToStart
+    handled[0] = true
+  }
+)
 
-Events.onWildBattleOverride += proc { |_sender, e|
-  species = e[0]
-  level   = e[1]
-  handled = e[2]
-  next if handled[0] != nil
-  next if !pbInSafari?
-  handled[0] = pbSafariBattle(species, level)
-}
+EventHandlers.add(:on_calling_wild_battle, :safari_battle,
+  proc { |species, level, handled|
+    # handled is an array: [nil]. If [true] or [false], the battle has already
+    # been overridden (the boolean is its outcome), so don't do anything that
+    # would override it again
+    next if !handled[0].nil?
+    next if !pbInSafari?
+    handled[0] = pbSafariBattle(species, level)
+  }
+)
 
 def pbSafariBattle(species, level)
   # Generate a wild Pokémon based on the species and level
@@ -140,7 +145,7 @@ def pbSafariBattle(species, level)
   end
   pbSet(1, decision)
   # Used by the Poké Radar to update/break the chain
-  Events.onWildBattleEnd.trigger(nil, species, level, decision)
+  EventHandlers.trigger(:on_wild_battle_end, species, level, decision)
   # Return the outcome of the battle
   return decision
 end
diff --git a/Data/Scripts/018_Alternate battle modes/002_BugContest.rb b/Data/Scripts/018_Alternate battle modes/002_BugContest.rb
index e843f0286..2c7a1b002 100644
--- a/Data/Scripts/018_Alternate battle modes/002_BugContest.rb	
+++ b/Data/Scripts/018_Alternate battle modes/002_BugContest.rb	
@@ -286,36 +286,40 @@ def pbBugContestDecided?
   return pbBugContestState.decided?
 end
 
-Events.onMapChange += proc { |_sender, _e|
-  pbBugContestState.pbClearIfEnded
-}
+EventHandlers.add(:on_enter_map, :end_bug_contest,
+  proc { |_old_map_id|
+    pbBugContestState.pbClearIfEnded
+  }
+)
 
-Events.onMapSceneChange += proc { |_sender, e|
-  scene = e[0]
-  if pbInBugContest? && pbBugContestState.decision == 0 && BugContestState::TIME_ALLOWED > 0
+EventHandlers.add(:on_map_or_spriteset_change, :show_bug_contest_timer,
+  proc { |scene, _map_changed|
+    next if !pbInBugContest? || pbBugContestState.decision != 0 || BugContestState::TIME_ALLOWED == 0
     scene.spriteset.addUserSprite(
       TimerDisplay.new(pbBugContestState.timer,
                        BugContestState::TIME_ALLOWED * Graphics.frame_rate)
     )
-  end
-}
+  }
+)
 
-Events.onMapUpdate += proc { |_sender, _e|
-  if !$game_player.move_route_forcing && !pbMapInterpreterRunning? &&
-     !$game_temp.message_window_showing && pbBugContestState.expired?
-    pbMessage(_INTL("ANNOUNCER:  BEEEEEP!"))
+EventHandlers.add(:on_frame_update, :bug_contest_counter,
+  proc {
+    next if !pbBugContestState.expired?
+    next if $game_player.move_route_forcing || pbMapInterpreterRunning? ||
+            $game_temp.message_window_showing
+    pbMessage(_INTL("ANNOUNCER: BEEEEEP!"))
     pbMessage(_INTL("Time's up!"))
     pbBugContestState.pbStartJudging
-  end
-}
+  }
+)
 
-Events.onMapChanging += proc { |_sender, e|
-  newmapID = e[0]
-  if pbInBugContest? && pbBugContestState.pbOffLimits?(newmapID)
+EventHandlers.add(:on_leave_map, :end_bug_contest,
+  proc { |new_map_id, new_map|
+    next if !pbInBugContest? || !pbBugContestState.pbOffLimits?(new_map_id)
     # Clear bug contest if player flies/warps/teleports out of the contest
     pbBugContestState.pbEnd(true)
-  end
-}
+  }
+)
 
 def pbBugContestStartOver
   $player.party.each do |pkmn|
@@ -326,19 +330,21 @@ def pbBugContestStartOver
   pbBugContestState.pbStartJudging
 end
 
-Events.onWildBattleOverride += proc { |_sender, e|
-  species = e[0]
-  level   = e[1]
-  handled = e[2]
-  next if handled[0] != nil
-  next if !pbInBugContest?
-  handled[0] = pbBugContestBattle(species, level)
-}
+EventHandlers.add(:on_calling_wild_battle, :bug_contest_battle,
+  proc { |species, level, handled|
+    # handled is an array: [nil]. If [true] or [false], the battle has already
+    # been overridden (the boolean is its outcome), so don't do anything that
+    # would override it again
+    next if !handled[0].nil?
+    next if !pbInBugContest?
+    handled[0] = pbBugContestBattle(species, level)
+  }
+)
 
 def pbBugContestBattle(species, level)
   # Record information about party Pokémon to be used at the end of battle (e.g.
   # comparing levels for an evolution check)
-  Events.onStartBattle.trigger(nil)
+  EventHandlers.trigger(:on_start_battle)
   # Generate a wild Pokémon based on the species and level
   pkmn = pbGenerateWildPokemon(species, level)
   foeParty = [pkmn]
@@ -387,7 +393,7 @@ def pbBugContestBattle(species, level)
   end
   pbSet(1, decision)
   # Used by the Poké Radar to update/break the chain
-  Events.onWildBattleEnd.trigger(nil, species, level, decision)
+  EventHandlers.trigger(:on_wild_battle_end, species, level, decision)
   # Return false if the player lost or drew the battle, and true if any other result
   return (decision != 2 && decision != 5)
 end