diff --git a/Data/Scripts/012_Battle/002_Move/002_Move_Usage.rb b/Data/Scripts/012_Battle/002_Move/002_Move_Usage.rb
index 06a7d738b..dac3a3ded 100644
--- a/Data/Scripts/012_Battle/002_Move/002_Move_Usage.rb
+++ b/Data/Scripts/012_Battle/002_Move/002_Move_Usage.rb
@@ -164,7 +164,7 @@ class PokeBattle_Move
       return
     end
     # Disguise will take the damage
-    if !@battle.moldBreaker && isConst?(target.species,PBSpecies,:MIMIKYU) &&
+    if !@battle.moldBreaker && target.isSpecies?(:MIMIKYU) &&
        target.form==0 && isConst?(target.ability,PBAbilities,:DISGUISE)
       target.damageState.disguise = true
       return
diff --git a/Data/Scripts/012_Battle/008_BattleHandlers_Items.rb b/Data/Scripts/012_Battle/008_BattleHandlers_Items.rb
index 29e679297..5e1ae3943 100644
--- a/Data/Scripts/012_Battle/008_BattleHandlers_Items.rb
+++ b/Data/Scripts/012_Battle/008_BattleHandlers_Items.rb
@@ -852,7 +852,7 @@ BattleHandlers::DamageCalcTargetItem.add(:COLBURBERRY,
 
 BattleHandlers::DamageCalcTargetItem.add(:DEEPSEASCALE,
   proc { |item,user,target,move,mults,baseDmg,type|
-    if isConst?(target.species,PBSpecies,:CLAMPERL) && move.specialMove?
+    if target.isSpecies?(:CLAMPERL) && move.specialMove?
       mults[DEF_MULT] *= 2
     end
   }
@@ -889,8 +889,7 @@ BattleHandlers::DamageCalcTargetItem.add(:KEBIABERRY,
 
 BattleHandlers::DamageCalcTargetItem.add(:METALPOWDER,
   proc { |item,user,target,move,mults,baseDmg,type|
-    if isConst?(target.species,PBSpecies,:DITTO) &&
-       !target.effects[PBEffects::Transform]
+    if target.isSpecies?(:DITTO) && !target.effects[PBEffects::Transform]
       mults[DEF_MULT] = (mults[DEF_MULT]*1.5).round
     end
   }
@@ -935,8 +934,7 @@ BattleHandlers::DamageCalcTargetItem.add(:SHUCABERRY,
 BattleHandlers::DamageCalcTargetItem.add(:SOULDEW,
   proc { |item,user,target,move,mults,baseDmg,type|
     next if NEWEST_BATTLE_MECHANICS
-    next if !isConst?(target.species,PBSpecies,:LATIAS) &&
-            !isConst?(target.species,PBSpecies,:LATIOS)
+    next if !target.isSpecies?(:LATIAS) && !target.isSpecies?(:LATIOS)
     if move.specialMove? && !user.battle.rules["souldewclause"]
       mults[DEF_MULT] = (mults[DEF_MULT]*1.5).round
     end
diff --git a/Data/Scripts/013_Overworld/007_PField_Encounters.rb b/Data/Scripts/013_Overworld/007_PField_Encounters.rb
index 61e7fa6fe..1533f62c4 100644
--- a/Data/Scripts/013_Overworld/007_PField_Encounters.rb
+++ b/Data/Scripts/013_Overworld/007_PField_Encounters.rb
@@ -338,9 +338,9 @@ class PokemonEncounters
     end
     firstPkmn = $Trainer.firstPokemon
     if firstPkmn
-      if isConst?(firstPkmn.item,PBItems,:CLEANSETAG)
+      if firstPkmn.hasItem?(:CLEANSETAG)
         encount = encount*2/3
-      elsif isConst?(firstPkmn.item,PBItems,:PUREINCENSE)
+      elsif firstPkmn.hasItem?(:PUREINCENSE)
         encount = encount*2/3
       else   # Ignore ability effects if an item effect applies
         if isConst?(firstPkmn.ability,PBAbilities,:STENCH)
diff --git a/Data/Scripts/013_Overworld/013_PField_DayCare.rb b/Data/Scripts/013_Overworld/013_PField_DayCare.rb
index b390142f0..cbf0ef25d 100644
--- a/Data/Scripts/013_Overworld/013_PField_DayCare.rb
+++ b/Data/Scripts/013_Overworld/013_PField_DayCare.rb
@@ -220,7 +220,7 @@ def pbDayCareGenerateEgg
      isConst?(babyspecies,PBSpecies,:ROCKRUFF) ||
      isConst?(babyspecies,PBSpecies,:MINIOR)
     newForm = mother.form
-    newForm = 0 if isConst?(mother.species,PBSpecies,:MOTHIM)
+    newForm = 0 if mother.isSpecies?(:MOTHIM)
     egg.form = newForm
   end
   # Inheriting Alolan form
@@ -280,13 +280,11 @@ def pbDayCareGenerateEgg
   end
   # Volt Tackle
   lightball = false
-  if (isConst?(father.species,PBSpecies,:PIKACHU) ||
-      isConst?(father.species,PBSpecies,:RAICHU)) &&
+  if (father.isSpecies?(:PIKACHU) || father.isSpecies?(:RAICHU)) &&
       father.hasItem?(:LIGHTBALL)
     lightball = true
   end
-  if (isConst?(mother.species,PBSpecies,:PIKACHU) ||
-      isConst?(mother.species,PBSpecies,:RAICHU)) &&
+  if (mother.isSpecies?(:PIKACHU) || mother.isSpecies?(:RAICHU)) &&
       mother.hasItem?(:LIGHTBALL)
     lightball = true
   end
diff --git a/Data/Scripts/016_Pokemon/001_PokeBattle_Pokemon.rb b/Data/Scripts/016_Pokemon/001_PokeBattle_Pokemon.rb
index c37278621..c32d1e77e 100644
--- a/Data/Scripts/016_Pokemon/001_PokeBattle_Pokemon.rb
+++ b/Data/Scripts/016_Pokemon/001_PokeBattle_Pokemon.rb
@@ -796,7 +796,7 @@ class PokeBattle_Pokemon
     if gain>0
       gain += 1 if @obtainMap==$game_map.map_id
       gain += 1 if self.ballused==pbGetBallType(:LUXURYBALL)
-      gain = (gain*1.5).floor if isConst?(self.item,PBItems,:SOOTHEBELL)
+      gain = (gain*1.5).floor if self.hasItem?(:SOOTHEBELL)
     end
     @happiness += gain
     @happiness = [[255,@happiness].min,0].max
diff --git a/Data/Scripts/017_UI/017_PScreen_PokemonStorage.rb b/Data/Scripts/017_UI/017_PScreen_PokemonStorage.rb
index eaa0fa106..16158b79a 100644
--- a/Data/Scripts/017_UI/017_PScreen_PokemonStorage.rb
+++ b/Data/Scripts/017_UI/017_PScreen_PokemonStorage.rb
@@ -1715,7 +1715,7 @@ class PokemonStorageScreen
           if heldpoke || selected[0]==-1
             p = (heldpoke) ? heldpoke : @storage[-1,index]
             p.formTime = nil if p.respond_to?("formTime")
-            p.form     = 0 if isConst?(p.species,PBSpecies,:SHAYMIN)
+            p.form     = 0 if p.isSpecies?(:SHAYMIN)
             p.heal
           end
           @scene.pbStore(selected,heldpoke,destbox,firstfree)
diff --git a/Data/Scripts/017_UI/021_PScreen_Evolution.rb b/Data/Scripts/017_UI/021_PScreen_Evolution.rb
index 7f52d431e..d1057cc85 100644
--- a/Data/Scripts/017_UI/021_PScreen_Evolution.rb
+++ b/Data/Scripts/017_UI/021_PScreen_Evolution.rb
@@ -587,7 +587,7 @@ class PokemonEvolutionScene
     # Modify Pokémon to make it evolved
     @pokemon.species = @newspecies
     @pokemon.name    = newspeciesname if @pokemon.name==oldspeciesname
-    @pokemon.form    = 0 if isConst?(@pokemon.species,PBSpecies,:MOTHIM)
+    @pokemon.form    = 0 if @pokemon.isSpecies?(:MOTHIM)
     @pokemon.calcStats
     # See and own evolved species
     $Trainer.seen[@newspecies]  = true
diff --git a/Data/Scripts/017_UI/024_PScreen_PurifyChamber.rb b/Data/Scripts/017_UI/024_PScreen_PurifyChamber.rb
index fc1df25be..941819788 100644
--- a/Data/Scripts/017_UI/024_PScreen_PurifyChamber.rb
+++ b/Data/Scripts/017_UI/024_PScreen_PurifyChamber.rb
@@ -182,7 +182,7 @@ class PurifyChamber # German: der Kryptorbis
     return false if !shadow
     return false if shadow.heartgauge!=0
     # Define an exception for Lugia
-    if isConst?(shadow.species,PBSpecies,:LUGIA)
+    if shadow.isSpecies?(:LUGIA)
       maxtempo=PurifyChamber.maximumTempo()
       for i in 0...NUMSETS
         return false if @sets[i].tempo!=maxtempo