Stat modifier

When a stat is used in a calculation in , a number of stat modifiers may be applied during the calculation. During a battle, a Pokémon's effective stats may be raised or lowered by certain moves, Abilities, and held items. Some attacks may only have a chance of raising or lowering stats, while certain Abilities and held items may require a triggering event to activate any stat modifications. Stat modifiers always reset when the affected Pokémon exits the battlefield.
==Stages==
The modifiers conferred by most moves operate on a sliding scale of stages (also known as stat ranks in Pokémon Masters EX). When a given stat is raised or lowered, its current stage is increased or decreased by the amount dictated by the move, up to a maximum of +6 or a minimum of −6. A given stage corresponds to a given multiplier that will modify the stat when it is used in battle calculations. The exact multipliers for stages are detailed in a later section below. Note that prior to Generation III, no stat can fall below 1 or rise above 999; any further modifiers will be treated as if the stat was capped regardless of whether the stat is at −6 or +6 or not.
HP is the only stat that has no stages. Dynamax is the only mechanic that can directly change a Pokémon's maximum HP without changing the variables in the HP-determining formula.
In the Generation and core series games, when an in-game opponent outside of the uses a status move that would decrease one of the target's stats, that move has a 25% chance to fail in addition to its normal chance to miss.pret/pokered/engine/battle/effects.asmpret/pokegold/engine/battle/effect_commands.asm
The stages of all of a Pokémon's stats are reset to zero when the Pokémon is withdrawn or affected by the moves or . When a move lands a critical hit in Generations I and II, it ignores all changes to stat stages. From Generation III onward, critical hits ignore the attacker's negative stat stages and the defender's positive stat stages. If a Pokémon is under the effect of , , , or , its stat stages can only be lowered through self-inflicted methods such as . , , and ignore changes to the target's physical Defense and Evasion stat stages. , , and can cause subsequent moves to ignore the target's Evasion stat stages. From Generation V onward, if a Pokémon's Ability is , then any changes to stages are doubled. If a Pokémon's Ability is , then any changes to stages are reversed. reverses the stages of all of the target's stats.
While some moves, Abilities, and held items may also modify the stages of a Pokémon's stats, others may apply unique multipliers that are separate from — and thus can stack with — stages. Examples include the move , which multiplies Speed by 2 times, the Ability , which temporarily halves Attack and Speed, and the held item Choice Band, which multiplies Attack by 1.5 times.
From Generation V onward, the Speed stat has boundaries put in place that don't apply to any other stat. After taking stat stages and all other modifiers into account, if the resulting Speed stat is above 10000, it is reduced to 10000. The Speed stat is then subtracted from 10000 if and only if is in effect, and finally if the Speed stat is greater than or equal to 8192, it is reduced by 8192 to produce the final figure used in speed comparisons. As a result, a Pokémon that runs into the limit of 10000 Speed is further reduced to an effective 1808.
===In-battle modification===
In the table below, anything in italics is capable of modifying one stat out of two or more and may not always affect the same one.
Stat	Raisers	Raisers	Raisers	Raisers	Reducers	Reducers
Stat	 	 	 	 	 	
 	
{| style="margin:auto"	<ab>1 stage
</ab>	<ab>1 stage
2 stages
≥3 stages
Other
</ab>	 	 	
===Stage modification quotes===
The "Pokémon" identifier in the quotes below includes a prefix that varies depending on the situation; most wild Pokémon (but not all) and opposing Pokémon have one. If a move would raise a stat that is too high or lower a stat that is too low as a secondary effect, a quote will not be shown. From Generation V onwards, the game will take into account the effective change (for example, not +2 for a stat at +5); additionally moves that list multiple quotes will always state each stat separately, even if they're all capped.
In Generation II, if still has a stat to raise, it will not display any text for the capped stats. In Generation III, Curse will instead fail if all stats are capped. In Generation III and IV, it will always list each stat separately when it does so.
Change 	Generation I 	Generation II 	Generation III 	Generation IV 	Generation V 	Generation VI 	Generation VII 	Generation VIII 	Generation IX 	
too high 	Nothing happened! 	<Pokémon>'s <stat> won't rise anymore! 	<Pokémon>'s <stat> won't go higher! 	<Pokémon>'s <stat> won't go higher! 	<Pokémon>'s <stat> won't go any higher!	<Pokémon>'s <stat> won't go any higher!	<Pokémon>'s <stat> won't go any higher!	<Pokémon>'s <stat> won't go any higher!	<Pokémon>'s <stat> won't go any higher!	
multiple too high	 	<Pokémon>'s <sc>Ability</sc> won't rise anymore!	<Pokémon>'s stats won't go any higher!	<Pokémon>'s stats won't go any higher!	 	 	 	 	 	
+1 	<Pokémon>'s <stat> rose! 	<Pokémon>'s <stat> went up! 	<Pokémon>'s <stat> rose! 	<Pokémon>'s <stat> rose! 	<Pokémon>'s <stat> rose! 	<Pokémon>'s <stat> rose! 	<Pokémon>'s <stat> rose! 	<Pokémon>'s <stat> rose! 	<Pokémon>'s <stat> rose! 	
+2 	<Pokémon>'s <stat> greatly rose!	<Pokémon>'s <stat> went way up! 	<Pokémon>'s <stat> sharply rose! 	<Pokémon>'s <stat> sharply rose! 	<Pokémon>'s <stat> rose sharply! 	<Pokémon>'s <stat> rose sharply! 	<Pokémon>'s <stat> rose sharply! 	<Pokémon>'s <stat> rose sharply! 	<Pokémon>'s <stat> rose sharply! 	<Pokémon>'s <stat> rose sharply!
+3 or higher 	 	 	 	 	<Pokémon>'s <stat> rose drastically! 	<Pokémon>'s <stat> rose drastically! 	<Pokémon>'s <stat> rose drastically! 	<Pokémon>'s <stat> rose drastically! 	<Pokémon>'s <stat> rose drastically! 	
multiple too low 	 	 	<Pokémon>'s stats won't go any lower! 	<Pokémon>'s stats won't go any lower! 	 	 	 	 	 	
too low 	Nothing happened! 	<Pokémon>'s <stat> won't drop anymore! 	<Pokémon>'s <stat> won't go lower! 	<Pokémon>'s <stat> won't go lower! 	<Pokémon>'s <stat> won't go any lower! 	<Pokémon>'s <stat> won't go any lower! 	<Pokémon>'s <stat> won't go any lower! 	<Pokémon>'s <stat> won't go any lower! 	<Pokémon>'s <stat> won't go any lower! 	
−1 	<Pokémon>'s <stat> fell! 	<Pokémon>'s <stat> fell! 	<Pokémon>'s <stat> fell! 	<Pokémon>'s <stat> fell! 	<Pokémon>'s <stat> fell! 	<Pokémon>'s <stat> fell! 	<Pokémon>'s <stat> fell! 	<Pokémon>'s <stat> fell! 	<Pokémon>'s <stat> fell! 	
−2 	<Pokémon>'s <stat> greatly fell!	<Pokémon>'s <stat> sharply fell! 	<Pokémon>'s <stat> harshly fell! 	<Pokémon>'s <stat> harshly fell! 	<Pokémon>'s <stat> harshly fell! 	<Pokémon>'s <stat> harshly fell! 	<Pokémon>'s <stat> harshly fell! 	<Pokémon>'s <stat> harshly fell! 	<Pokémon>'s <stat> harshly fell! 	
−3 or lower 	 	 	 	 	<Pokémon>'s <stat> severely fell! 	<Pokémon>'s <stat> severely fell! 	<Pokémon>'s <stat> severely fell! 	<Pokémon>'s <stat> severely fell! 	<Pokémon>'s <stat> severely fell! 	
===Stage multipliers===
When a move is used that increases or decreases a stat of a Pokémon in battle, it will be multiplied according to the following fractions, depending on the generation:
;For Attack, Defense, Special, Sp. Attack, Sp. Defense, and Speed
 Stage multipliers
Stage 	−6 	−5 	−4 	−3 	−2 	−1 	0 	+1 	+2 	+3 	+4 	+5 	+6
Gen I-II	25/100	28/100	33/100	40/100	50/100	66/100	100/100	150/100	200/100	250/100	300/100	350/100	400/100
Gen III+	2/8 	2/7 	2/6 	2/5 	2/4 	2/3 	2/2 	3/2 	4/2 	5/2 	6/2 	7/2 	8/2
;For accuracy and evasion
 Stage multipliers
Stage (accuracy) 	−6 	−5 	−4 	−3 	−2 	−1 	0 	+1 	+2 	+3 	+4 	+5 	+6
Stage (evasion) 	+6 	+5 	+4 	+3 	+2 	+1 	0 	−1 	−2 	−3 	−4 	−5 	−6
Gen I handheld games	25/100	28/100	33/100	40/100	50/100	66/100	100/100	150/100	200/100	250/100	300/100	350/100	400/100
Pokémon Stadium 	1/3 	36/100	43/100	50/100	66/100	75/100	100/100	133/100	166/100	200/100	233/100	266/100	300/100
Gen II 	33/100	36/100	43/100	50/100	60/100	75/100	100/100	133/100	166/100	200/100	233/100	266/100	300/100
Gen III-IV 	33/100	36/100	43/100	50/100	60/100	75/100	100/100	133/100	166/100	200/100	233/100	266/100	300/100
Gen V+ 	3/9 	3/8 	3/7 	3/6 	3/5 	3/4 	3/3 	4/3 	5/3 	6/3 	7/3 	8/3 	9/3
In Generations I and II, accuracy and evasion stages are resolved separately and both multipliers are applied to the move's accuracy to determine the final chance of a move hitting or missing. For example, a Pokémon with −1 accuracy using a move that has 100% accuracy on a target with +1 evasion would have a {66 \over 100} \times {66 \over 100} = 43.56\% chance of hitting in Generation I, or a {75 \over 100} \times {75 \over 100} = 56.25\% chance of hitting in Generation II. In Generation III, this was changed so that the stages of the accuracy and evasion stats are now combined before determining the multiplier, with the evasion stage subtracted from the accuracy stage. Therefore, in the above situation, the attacking Pokémon would have a {60 \over 100} = 60\% chance of hitting.Dragonfly Cave on stat stages mechanics
Additionally, the combined stages are capped at -6 and +6 from Generation III onward (extra stages are surplus), meaning that a Pokémon with minimum accuracy attacking a target with maximum evasion will have no lower than a {33 \over 100} = 33\% chance to hit. (For comparison, in Generation II, the attacker would only have a {33 \over 100} \times {33 \over 100} = 10.89\% chance of hitting.)
In Generation IV, if a Pokémon's Ability is , then its stats will be multiplied as if the stat change was doubled. For example, a stat raised by one stage will be multiplied as if it were raised by two stages.
==List of Abilities, moves, and items affected by stat changes==
====Abilities====
{| border=1 width="100%" style="margin:auto; text-align:center; background:#FFF; border:1px solid #ddf; border-collapse:collapse"	 	
Name 	Effect 	Generation
Defiant 	Boosts the Pokémon's Attack stat sharply when its stats are lowered.	V
Competitive	Boosts the Sp. Atk stat sharply when a stat is lowered. 	VI
====Moves====
{| border=1 width="100%" style="margin:auto; text-align:center; background:#FFF; border:1px solid #ddf; border-collapse:collapse"	 	
Name	Effect 	Generation
 	The more the target has powered up with stat changes, the greater the move's power. 	IV
 	The user attacks the target with stored power. The more the user's stats are boosted, the greater the move's power. 	V
 	The user boasts its strength and attacks the target. The more the user's stats are boosted, the greater the move's power. 	VII
 	The user attacks with energy from jealousy. This leaves all opposing Pokémon that have had their stats boosted during the turn with a burn. 	VIII
 	The user lashes out to vent its frustration toward the target. This move's power is doubled if the user's stats were lowered during this turn.	VIII
====Items====
{| border=1 width="100%" style="margin:auto; text-align:center; background:#FFF; border:1px solid #ddf; border-collapse:collapse"	 	
Name 	Effect 	Generation
Ginema Berry 	Raises a lowered stat in battle. 	III
White Herb 	Restores any lowered stat in battle. 	III
Adrenaline Orb	If held by a Pokémon, it boosts Speed when intimidated. 	VII
Eject Pack 	When the holder's stats are lowered, it will be switched out of battle.	VIII
====
In , stat modifiers work much differently that they do in other core series games:
* Stat modifiers expire after the affected Pokémon has executed a certain number of turns or switches out.
* Stat modifiers for Attack also affect Sp. Atk equally, and vice versa.
* Stat modifiers for Defense also affect Sp. Def equally, and vice versa.
* Stat modifiers each only have one stage multiplier: a ×1.5 boost or a ×2/3 drop.
** If a stat modifier is applied to a Pokémon that already has that same modifier, then it will simply overwrite its number of turns remaining.
** If a stat modifier is applied to a Pokémon with the opposite modifier, then it will cancel it out.
Modifier 	In-game description 	Details 	Causes
Power Boost	The Pokémon's offensive stats are raised, boosting its Attack and Sp. Atk stats. 	Power Boost indicates that a Pokémon's offensive stats are raised, increasing the damage it deals with its moves by 50%. If the Pokémon is already affected by Power Drop, it will cancel it out instead. It is usually caused by moves that can raise Attack or Sp. Atk in other core series games. 	
;4 turns
 • • 
;5 turns
 •
Power Drop 	The Pokémon's offensive stats are lowered, reducing its Attack and Sp. Atk stats. 	Power Drop indicates that a Pokémon's offensive stats are lowered, decreasing the damage it deals by a third. If the Pokémon is already affected by Power Boost, it will cancel it out instead. It is usually caused by moves that can lower Attack or Sp. Atk in other core series games. 	
;3 turns
 • 
 • • 
;5 turns
Guard Boost	The Pokémon's defensive stats are raised, boosting its Defense and Sp. Def stats. 	Guard Boost indicates that a Pokémon's defensive stats are raised, decreasing the damage it takes from attacks by a third. If the Pokémon is already affected by Guard Drop, it will cancel it out instead. It is usually caused by moves that can raise Defense or Sp. Def in other core series games.	
;4 turns
;5 turns
Guard Drop 	The Pokémon's defensive stats are lowered, reducing its Defense and Sp. Def stats.	Guard Drop indicates that a Pokémon's defensive stats are lowered, increasing the damage it takes from attacks by 50%. If the Pokémon is already affected by Guard Boost, it will cancel it out instead. It is usually caused by moves that can lower Defense or Sp. Def in other core series games. 	
;3 turns
 •
==References==
Category:Game mechanics