Team Validator

The TeamValidator class handles team validation and learnset checking for Pokemon Showdown. It ensures teams comply with format rules, move legality, stat constraints, and event restrictions.

Constructor

Creates a new TeamValidator instance for a specific format.

new TeamValidator(format: string | Format, dex?: ModdedDex)

format

string | Format

Format name (e.g., “gen9ou”, “gen8vgc2022”) or Format object

dex

ModdedDex

ModdedDex instance. Defaults to the standard Dex.

import { TeamValidator, Teams } from './sim';

const validator = new TeamValidator('gen9ou');
const team = Teams.unpack('Garchomp||choiceband|roughskin|outrage,earthquake,stoneedge,firefang|Jolly|,252,,,4,252|||||');

const problems = validator.validateTeam(team);
if (problems) {
  console.log('Invalid team:', problems);
} else {
  console.log('Team is valid!');
}

Properties

format

Format

The Format object for this validator

dex

ModdedDex

The ModdedDex instance used for validation (adjusted for the format)

gen

number

The generation number for this format

ruleTable

RuleTable

The parsed rule table for this format

minSourceGen

number

Minimum generation a Pokemon must be from (e.g., 6 if Pentagon required)

Methods

validateTeam()

Validates an entire team for format legality.

validateTeam(
  team: PokemonSet[] | null,
  options?: {
    removeNicknames?: boolean,
    skipSets?: { [name: string]: { [key: string]: boolean } }
  }
): string[] | null

team

PokemonSet[] | null

Team to validate (null for formats with auto-generated teams)

options

object

Validation options

removeNicknames

boolean

Remove nicknames and use species names instead

skipSets

{ [name: string]: { [key: string]: boolean } }

Skip validation for specific sets

return

string[] | null

Array of problem strings if invalid, or null if valid

import { TeamValidator, Teams } from './sim';

const validator = new TeamValidator('gen9ou');
const team = Teams.import(`
Garchomp @ Choice Band  
Ability: Rough Skin  
EVs: 252 Atk / 4 SpD / 252 Spe  
Jolly Nature  
- Outrage  
- Earthquake  
- Stone Edge  
- Fire Fang  
`);

const problems = validator.validateTeam(team);
if (problems) {
  problems.forEach(problem => console.log(problem));
} else {
  console.log('Valid team!');
}

Team validation checks team size limits, species clauses, tier restrictions, and calls validateSet() for each Pokemon.

validateSet()

Validates a single Pokemon set.

validateSet(
  set: PokemonSet,
  teamHas: AnyObject
): string[] | null

set

PokemonSet

Pokemon set to validate

teamHas

AnyObject

Object tracking what the team has (for clause checking). Modified in place.

return

string[] | null

Array of problem strings if invalid, or null if valid

import { TeamValidator } from './sim';

const validator = new TeamValidator('gen9ou');
const set = {
  name: 'Garchomp',
  species: 'Garchomp',
  item: 'Choice Band',
  ability: 'Rough Skin',
  moves: ['Outrage', 'Earthquake', 'Stone Edge', 'Fire Fang'],
  nature: 'Jolly',
  evs: { hp: 0, atk: 252, def: 0, spa: 0, spd: 4, spe: 252 },
  ivs: { hp: 31, atk: 31, def: 31, spa: 31, spd: 31, spe: 31 },
  level: 100,
  gender: ''
};

const teamHas = {};
const problems = validator.validateSet(set, teamHas);

if (problems) {
  console.log('Invalid set:', problems);
} else {
  console.log('Valid set!');
  console.log('Team has:', teamHas); // Tracks species, abilities, items, etc.
}

baseValidateTeam()

Base team validation logic without custom format overrides.

baseValidateTeam(
  team: PokemonSet[] | null,
  options?: {
    removeNicknames?: boolean,
    skipSets?: { [name: string]: { [key: string]: boolean } }
  }
): string[] | null

Same parameters and return type as validateTeam(), but skips format-specific validateTeam overrides.

import { TeamValidator } from './sim';

const validator = new TeamValidator('gen9ou');
const team = [/* ... */];

// Uses base validation only
const problems = validator.baseValidateTeam(team);

validateStats()

Validates EVs, IVs, Hidden Power, and stat-related legality.

validateStats(
  set: PokemonSet,
  species: Species,
  setSources: PokemonSources,
  pokemonGoProblems: string[] | null
): string[]

set

PokemonSet

Pokemon set to validate

species

Species

Species data

setSources

PokemonSources

Possible sources for this Pokemon

pokemonGoProblems

string[] | null

Pokemon GO validation problems

return

string[]

Array of stat-related problems

const set = {
  species: 'Garchomp',
  evs: { hp: 252, atk: 252, def: 252, spa: 0, spd: 0, spe: 0 }, // 756 total
  ivs: { hp: 31, atk: 31, def: 31, spa: 31, spd: 31, spe: 31 },
  // ... other properties
};

const problems = validator.validateStats(set, species, setSources, null);
// Returns: ["Garchomp has 756 total EVs, which is more than this format's limit of 510."]

validateStats() enforces:

EV limits (default 510 total, 252 per stat)
IV ranges (0-31, or 0-30 for Gen 1-2 DVs)
Hidden Power type matching IVs
Legendary 3-perfect-IV requirement (Gen 6+)
Gen 1-2 DV consistency (HP, gender, shininess)
Bottle Cap hyper training legality

getValidationSpecies()

Determines the out-of-battle and tier species for validation.

getValidationSpecies(set: PokemonSet): {
  outOfBattleSpecies: Species,
  tierSpecies: Species
}

set

PokemonSet

Pokemon set to analyze

return

{ outOfBattleSpecies: Species, tierSpecies: Species }

Object containing both species forms

outOfBattleSpecies

Species

Species used for learnset/event checking

tierSpecies

Species

Species used for tier/banlists (includes Mega/Primal forms)

const set = {
  species: 'Garchomp',
  item: 'Garchompite',
  // ...
};

const { outOfBattleSpecies, tierSpecies } = validator.getValidationSpecies(set);
console.log(outOfBattleSpecies.name); // "Garchomp"
console.log(tierSpecies.name);        // "Garchomp-Mega" (if obtainableformes rule)

getEventOnlyData()

Retrieves event data for event-only Pokemon.

getEventOnlyData(
  species: Species,
  noRecurse?: boolean
): { species: Species, eventData: EventInfo[] } | null

species

Species

Species to check

noRecurse

boolean

Don’t check prevo for event data

return

{ species: Species, eventData: EventInfo[] } | null

Event data object, or null if not event-only

const dex = validator.dex;
const mew = dex.species.get('Mew');
const eventData = validator.getEventOnlyData(mew);

if (eventData) {
  console.log(`${eventData.species.name} has ${eventData.eventData.length} events`);
  eventData.eventData.forEach((event, i) => {
    console.log(`Event ${i}: Gen ${event.generation}, Level ${event.level}`);
  });
}

PokemonSources Class

The PokemonSources class represents possible sources for obtaining a Pokemon with a specific set.

class PokemonSources {
  sources: PokemonSource[];      // Specific sources (e.g., "7S0", "8E")
  sourcesBefore: number;         // Any source from this gen or earlier
  sourcesAfter: number;          // Requires this gen or later
  isHidden: boolean | null;      // Has Hidden Ability
  limitedEggMoves?: ID[] | null; // Egg moves requiring specific fathers
  moveEvoCarryCount: number;     // Moves requiring evolution
  dreamWorldMoveCount: number;   // Dream World moves
  // ... additional properties
}

Constructor

new PokemonSources(sourcesBefore?: number, sourcesAfter?: number)

sourcesBefore

number

default:0

Allow all sources from this generation or earlier

sourcesAfter

number

default:0

Require sources from this generation or later

// Allow any Gen 8 or earlier source
const sources = new PokemonSources(8, 0);

// Require Gen 6+ sources (Pentagon)
const gen6plus = new PokemonSources(0, 6);

Methods

add()

Adds a specific source to the set.

add(source: PokemonSource, limitedEggMove?: ID | null): void

const sources = new PokemonSources();
sources.add('8S0');      // Event source
sources.add('7E');       // Egg source
sources.add('6L5');      // Level-up move in Gen 6

addGen()

Adds all sources from a generation or earlier.

addGen(sourceGen: number): void

const sources = new PokemonSources();
sources.addGen(7); // Allow all Gen 7 and earlier sources

minSourceGen() / maxSourceGen()

Gets the minimum or maximum generation in the source set.

minSourceGen(): number
maxSourceGen(): number

const sources = new PokemonSources();
sources.add('6L1');
sources.add('8M2');

console.log(sources.minSourceGen()); // 6
console.log(sources.maxSourceGen()); // 8

intersectWith()

Intersects this source set with another (for combining move restrictions).

intersectWith(other: PokemonSources): void

const sources1 = new PokemonSources();
sources1.add('7E');
sources1.add('8V');

const sources2 = new PokemonSources();
sources2.add('8V');
sources2.add('8L1');

// Keep only common sources
sources1.intersectWith(sources2);
// sources1.sources now contains only '8V'

Source Strings

Pokemon sources are encoded as strings:

// Format: [GEN][TYPE][INDEX] [SPECIES]
// Examples:
"8M2"      // TM/TR move in Gen 8
"7L1"      // Level-up move at level 1 in Gen 7
"6E"       // Egg move in Gen 6
"7S0"      // Event #0 in Gen 7
"5D"       // Dream World in Gen 5
"8V"       // Virtual Console/Let's Go transfer
"1ET"      // Tradeback egg in Gen 1

Validation Examples

Basic Team Validation

import { TeamValidator, Teams } from './sim';

const validator = new TeamValidator('gen9ou');

const teamString = `
Garchomp @ Choice Band  
Ability: Rough Skin  
EVs: 252 Atk / 4 SpD / 252 Spe  
Jolly Nature  
- Outrage  
- Earthquake  
- Stone Edge  
- Fire Fang  

Great Tusk @ Leftovers  
Ability: Protosynthesis  
EVs: 252 HP / 4 Atk / 252 Spe  
Jolly Nature  
- Earthquake  
- Rapid Spin  
- Ice Spinner  
- Knock Off  
`;

const team = Teams.import(teamString);
const problems = validator.validateTeam(team);

if (problems) {
  console.log('Team validation failed:');
  problems.forEach(problem => console.log(`  - ${problem}`));
} else {
  console.log('Team is legal!');
}

Validating Event Pokemon

import { TeamValidator, Teams } from './sim';

const validator = new TeamValidator('gen8ou');

// Victini with V-create (event-exclusive move)
const team = Teams.import(`
Victini @ Choice Band  
Ability: Victory Star  
EVs: 252 Atk / 4 SpD / 252 Spe  
Jolly Nature  
- V-create  
- Bolt Strike  
- U-turn  
- Trick  
`);

const problems = validator.validateTeam(team);
if (problems) {
  console.log('Event validation:', problems);
  // Will check if Victini's event allows this move combination
}

Checking Move Legality

import { TeamValidator, Teams } from './sim';

const validator = new TeamValidator('gen9ou');

// Illegal: Garchomp can't learn both Dragon Dance and Outrage
const illegalTeam = Teams.import(`
Garchomp @ Choice Band  
Ability: Rough Skin  
EVs: 252 Atk / 4 SpD / 252 Spe  
Jolly Nature  
- Outrage  
- Dragon Dance  
- Earthquake  
- Stone Edge  
`);

const problems = validator.validateTeam(illegalTeam);
if (problems) {
  console.log('Move legality issues:');
  problems.forEach(problem => console.log(`  ${problem}`));
}

VGC Format Validation

import { TeamValidator, Teams } from './sim';

// VGC 2023 Series 1
const validator = new TeamValidator('gen9vgc2023series1');

const vgcTeam = Teams.import(`
Flutter Mane @ Choice Specs  
Ability: Protosynthesis  
Level: 50  
EVs: 4 HP / 252 SpA / 252 Spe  
Timid Nature  
IVs: 0 Atk  
- Shadow Ball  
- Moonblast  
- Icy Wind  
- Thunderbolt  

Iron Hands @ Assault Vest  
Ability: Quark Drive  
Level: 50  
EVs: 252 HP / 252 Atk / 4 SpD  
Adamant Nature  
- Fake Out  
- Close Combat  
- Thunder Punch  
- Heavy Slam  
`);

const problems = validator.validateTeam(vgcTeam);
if (!problems) {
  console.log('VGC team is legal!');
}

Static Methods

fillStats()

Fills missing stats with default values.

static TeamValidator.fillStats(
  stats: Partial<StatsTable> | null,
  fillValue: number
): StatsTable

stats

Partial<StatsTable> | null

Partial stats object to fill

fillValue

number

Value to use for missing stats

return

StatsTable

Complete stats object with all six stats

import { TeamValidator } from './sim';

// Fill EVs with 0
const evs = TeamValidator.fillStats({ atk: 252, spe: 252 }, 0);
// Result: { hp: 0, atk: 252, def: 0, spa: 0, spd: 0, spe: 252 }

// Fill IVs with 31
const ivs = TeamValidator.fillStats(null, 31);
// Result: { hp: 31, atk: 31, def: 31, spa: 31, spd: 31, spe: 31 }

Error Handling

import { TeamValidator, Teams } from './sim';

try {
  const validator = new TeamValidator('invalidformat');
} catch (error) {
  console.error('Invalid format:', error.message);
  // Error: format 'invalidformat' should be a 'Format', but was a 'undefined'
}

const validator = new TeamValidator('gen9ou');
const team = Teams.unpack('InvalidData');

if (!team) {
  console.error('Failed to parse team');
} else {
  const problems = validator.validateTeam(team);
  if (problems) {
    console.log('Validation errors:');
    problems.forEach((problem, i) => {
      console.log(`${i + 1}. ${problem}`);
    });
  }
}

Battle API

Dex API

Teams API

Protocol Reference

Command-Line Tools

Constructor

Properties

Methods

validateTeam()

validateSet()

baseValidateTeam()

validateStats()

getValidationSpecies()

getEventOnlyData()

PokemonSources Class

Constructor

Methods

add()

addGen()

minSourceGen() / maxSourceGen()

intersectWith()

Source Strings

Validation Examples

Basic Team Validation

Validating Event Pokemon

Checking Move Legality

VGC Format Validation

Static Methods

fillStats()

Error Handling

See Also

Build docs developers (and LLMs) love

Battle API

Dex API

Teams API

Protocol Reference

Command-Line Tools

​Constructor

​Properties

​Methods

​validateTeam()

​validateSet()

​baseValidateTeam()

​validateStats()

​getValidationSpecies()

​getEventOnlyData()

​PokemonSources Class

​Constructor

​Methods

​add()

​addGen()

​minSourceGen() / maxSourceGen()

​intersectWith()

​Source Strings

​Validation Examples

​Basic Team Validation

​Validating Event Pokemon

​Checking Move Legality

​VGC Format Validation

​Static Methods

​fillStats()

​Error Handling

​See Also

Build docs developers (and LLMs) love

Constructor

Properties

Methods

validateTeam()

validateSet()

baseValidateTeam()

validateStats()

getValidationSpecies()

getEventOnlyData()

PokemonSources Class

Constructor

Methods

add()

addGen()

minSourceGen() / maxSourceGen()

intersectWith()

Source Strings

Validation Examples

Basic Team Validation

Validating Event Pokemon

Checking Move Legality

VGC Format Validation

Static Methods

fillStats()

Error Handling

See Also