Pokemon Game Mechanics

Pokemon game mechanics are the underlying systems that govern how Pokemon games function. These include battle mechanics, stat systems, breeding, and various features that have evolved across generations.

Overview

Pokemon games are built on several interconnected systems:

System	Purpose
Battle System	Turn-based combat
Stat System	Pokemon attributes
Type System	Strengths/weaknesses
Evolution	Pokemon growth
Breeding	Creating new Pokemon
Catching	Acquiring Pokemon

Core Statistics

Base Stats

Every Pokemon species has six base stats that determine its capabilities:

Stat	Abbreviation	Effect
HP	HP	Hit Points; determines damage tolerance
Attack	Atk	Physical move damage
Defense	Def	Physical damage reduction
Special Attack	SpA	Special move damage
Special Defense	SpD	Special damage reduction
Speed	Spe	Turn order; some move effects

Stat Calculation

Final stats are calculated using:

Stat = ((2 × Base + IV + EV/4) × Level/100 + 5) × Nature

For HP:

HP = (2 × Base + IV + EV/4) × Level/100 + Level + 10

Individual Values (IVs)

Aspect	Details
Range	0-31 per stat
Determination	Random at encounter/hatching
Max IVs	"Perfect" Pokemon have 31 in all stats
Inheritance	Breeding passes some IVs
Hyper Training	Can maximize IVs at max level

Effort Values (EVs)

Aspect	Details
Range	0-252 per stat
Total Cap	510 total EVs
Gain	Defeating Pokemon, vitamins, training
Effect	+1 stat per 4 EVs at level 100
Optimization	Typically 252/252/4 distribution

EV-Boosting Items

Item	Effect
Power Weight	+8 HP EVs per battle
Power Bracer	+8 Attack EVs per battle
Power Belt	+8 Defense EVs per battle
Power Lens	+8 Sp. Attack EVs per battle
Power Band	+8 Sp. Defense EVs per battle
Power Anklet	+8 Speed EVs per battle
Macho Brace	Doubles EV gain

Natures

Natures affect stat growth:

Nature	+10% Stat	-10% Stat
Adamant	Attack	Sp. Attack
Modest	Sp. Attack	Attack
Jolly	Speed	Sp. Attack
Timid	Speed	Attack
Bold	Defense	Attack
Impish	Defense	Sp. Attack
Calm	Sp. Defense	Attack
Careful	Sp. Defense	Sp. Attack
Brave	Attack	Speed
Quiet	Sp. Attack	Speed

Neutral natures (no change): Hardy, Docile, Serious, Bashful, Quirky

Battle System

Turn Structure

Speed Check - Faster Pokemon acts first
Priority Check - Priority moves go before regular moves
Move Selection - Trainer chooses action
Move Execution - Damage calculation and effects
End of Turn - Weather, status damage, item effects

Damage Calculation

Damage = ((2 × Level/5 + 2) × Power × A/D) / 50 + 2) × Modifiers

Where:

Level = Attacker's level
Power = Move's base power
A = Attacker's Attack or Sp. Attack
D = Defender's Defense or Sp. Defense

Damage Modifiers

Modifier	Effect
STAB	1.5x for same-type moves
Type Effectiveness	0.5x, 1x, 2x, or 4x
Critical Hit	1.5x damage
Weather	1.5x or 0.5x for certain types
Random	0.85-1.00 multiplier
Burn	0.5x physical damage

Priority Brackets

Priority	Examples
+5	Helping Hand
+4	Protect, Detect
+3	Fake Out, Quick Guard
+2	Extreme Speed, Follow Me
+1	Quick Attack, Mach Punch, Aqua Jet
0	Most moves
-1	Vital Throw
-3	Focus Punch
-5	Counter, Mirror Coat
-6	Roar, Whirlwind, Circle Throw
-7	Trick Room

Status Conditions

Non-Volatile (persist after battle)

Status	Effect
Burn	1/16 HP damage, halves Attack
Paralysis	25% chance to skip turn, halves Speed
Poison	1/8 HP damage per turn
Badly Poisoned	Increasing damage (1/16, 2/16, etc.)
Sleep	Cannot act for 1-3 turns
Freeze	Cannot act until thawed

Volatile (cleared when switching)

Status	Effect
Confusion	33% chance to hurt self
Infatuation	50% chance to skip turn
Flinch	Skip turn (same turn only)
Leech Seed	Drains HP each turn
Curse (Ghost)	1/4 HP damage per turn

Evolution

Evolution Methods

Method	Examples
Level Up	Most Pokemon (Bulbasaur → Ivysaur at Lv. 16)
Stone	Pikachu → Raichu (Thunder Stone)
Trade	Haunter → Gengar
Trade with Item	Poliwhirl → Politoed (King's Rock)
Friendship	Eevee → Espeon/Umbreon
Location	Magneton → Magnezone (magnetic areas)
Time of Day	Eevee → Espeon (day) / Umbreon (night)
Know Move	Steenee → Tsareena (knowing Stomp)
Gender	Combee → Vespiquen (female only)

Evolution Stones

Stone	Evolutions
Fire Stone	Vulpix, Growlithe, Eevee
Water Stone	Poliwhirl, Shellder, Eevee
Thunder Stone	Pikachu, Eevee
Leaf Stone	Gloom, Weepinbell, Exeggcute
Moon Stone	Nidorina, Nidorino, Clefairy
Sun Stone	Gloom, Sunkern
Shiny Stone	Togetic, Roselia
Dusk Stone	Murkrow, Misdreavus
Dawn Stone	Kirlia (male), Snorunt (female)
Ice Stone	Alolan Vulpix, Galarian Darumaka

Breeding

Basics

Aspect	Details
Location	Pokemon Day Care/Nursery
Requirements	Male + Female (same Egg Group) or Ditto
Result	Egg containing lowest evolution form
Species	Determined by mother (or non-Ditto parent)

Egg Groups

Group	Examples
Monster	Bulbasaur, Charmander, Tyranitar
Dragon	Dragonite, Salamence, Garchomp
Field	Eevee, Arcanine, Lucario
Human-Like	Machamp, Alakazam, Lucario
Water 1	Squirtle, Lapras, Dragonite
Fairy	Pikachu, Clefairy, Togepi
Amorphous	Gastly, Ditto, Rotom
Undiscovered	Legendaries, baby Pokemon

Inheritance

Trait	Rules
Species	Mother's species (or non-Ditto)
IVs	3 random IVs from parents (5 with Destiny Knot)
Nature	Random (or mother's with Everstone)
Ability	80% chance mother's ability (or HA if mother has HA)
Egg Moves	Father's compatible moves
Pokeball	Mother's ball (or father's if breeding with Ditto)

Breeding Items

Item	Effect
Destiny Knot	Passes 5 IVs instead of 3
Everstone	Passes holder's nature
Power Items	Guarantees passing specific IV

Catching Pokemon

Catch Rate Formula

Factor	Effect
HP	Lower HP = higher catch rate
Status	Sleep/Freeze = 2.5x, Others = 1.5x
Ball	Different balls have different modifiers
Catch Rate	Species-specific (3-255)

Poke Ball Types

Ball	Effect
Poke Ball	1x catch rate
Great Ball	1.5x catch rate
Ultra Ball	2x catch rate
Master Ball	100% catch rate
Quick Ball	5x on first turn
Dusk Ball	3.5x in caves/at night
Timer Ball	Up to 4x based on turns
Net Ball	3.5x for Water/Bug types
Repeat Ball	3.5x for previously caught species

Special Mechanics

Weather

Weather	Effects
Harsh Sunlight	Fire +50%, Water -50%, Solar Beam instant
Rain	Water +50%, Fire -50%, Thunder 100% accurate
Sandstorm	Rock +50% Sp. Def, non-immune take 1/16 HP
Hail/Snow	Blizzard 100% accurate, non-Ice take 1/16 HP

Terrain

Terrain	Effects
Electric	Electric +30%, prevents Sleep
Grassy	Grass +30%, 1/16 HP recovery
Psychic	Psychic +30%, no priority moves
Misty	Dragon -50%, prevents status

Abilities

Category	Examples
Weather	Drought, Drizzle, Sand Stream
Stat Boost	Intimidate, Speed Boost
Immunity	Levitate, Flash Fire, Volt Absorb
Contact	Rough Skin, Static, Flame Body
Priority	Prankster, Gale Wings

Held Items

Category	Examples
Power	Choice Band, Life Orb, Choice Specs
Protection	Focus Sash, Leftovers, Assault Vest
Speed	Choice Scarf, Quick Claw
Type Boost	Charcoal, Mystic Water, Magnet
Evolution	Eviolite (for NFE Pokemon)

Generation-Specific Mechanics

Mega Evolution (Gen VI-VII)

Aspect	Details
Requirement	Mega Stone + Key Stone
Effect	Temporary form change, +100 BST
Limitation	Once per battle

Z-Moves (Gen VII)

Aspect	Details
Requirement	Z-Crystal
Effect	Powerful one-time move
Limitation	Once per battle

Dynamax/Gigantamax (Gen VIII)

Aspect	Details
Requirement	Power Spots (Galar only)
Effect	HP doubles, moves become Max Moves
Duration	3 turns

Terastallization (Gen IX)

Aspect	Details
Requirement	Tera Orb
Effect	Changes Pokemon's type
Duration	Rest of battle
Benefit	STAB on Tera type

References

^Pokemon Game Series — Game Freak / Nintendo (1996-2024)
^Game Mechanics — Bulbapedia (2024)
^Mechanics Guide — Serebii.net (2024)
^Competitive Mechanics — Smogon University (2024)