diff --git a/bun.lock b/bun.lock
index 07c4c1afe..18b951d06 100644
--- a/bun.lock
+++ b/bun.lock
@@ -267,6 +267,11 @@
     "packages/pokemon": {
       "name": "@claude-code-best/pokemon",
       "version": "1.0.0",
+      "dependencies": {
+        "@pkmn/client": "^0.7.2",
+        "@pkmn/protocol": "^0.7.2",
+        "@pkmn/view": "^0.7.2",
+      },
     },
     "packages/remote-control-server": {
       "name": "@anthropic/remote-control-server",
@@ -975,6 +980,18 @@
 
     "@pinojs/redact": ["@pinojs/redact@0.4.0", "https://registry.npmmirror.com/@pinojs/redact/-/redact-0.4.0.tgz", {}, "sha512-k2ENnmBugE/rzQfEcdWHcCY+/FM3VLzH9cYEsbdsoqrvzAKRhUZeRNhAZvB8OitQJ1TBed3yqWtdjzS6wJKBwg=="],
 
+    "@pkmn/client": ["@pkmn/client@0.7.2", "", { "dependencies": { "@pkmn/data": "^0.10.2", "@pkmn/protocol": "^0.7.2" } }, "sha512-Jf40Nqp+ZAcM5wNEIrMKNdU2G0OKELtGNXmq2QYRcVsutDF/g9+Xm5Y9nK+mIw+bAgSVSmZKD5/Y1MpwxHgX9A=="],
+
+    "@pkmn/data": ["@pkmn/data@0.10.7", "", { "dependencies": { "@pkmn/dex-types": "^0.10.7" } }, "sha512-csUX8BU4RMHxl3nEF3gIOp1eq9+q3xh+ZaX+Nr1RZBqWF4L5PkBzUG36KKgU+lw92BmncDYm7S8t52lPhAmoXA=="],
+
+    "@pkmn/dex-types": ["@pkmn/dex-types@0.10.7", "", { "dependencies": { "@pkmn/types": "^4.0.0" } }, "sha512-ewinxJHyeLwYSOcDsy+2pq9e1mMYNXwBB9B3CZG2fvonrkxAyycR5AtLKPqE61480jPPxaZocOh+SLtUm648SA=="],
+
+    "@pkmn/protocol": ["@pkmn/protocol@0.7.2", "", { "dependencies": { "@pkmn/types": "^4.0.0" }, "bin": { "generate-handler": "generate-handler", "protocol-verifier": "protocol-verifier" } }, "sha512-3zRY9B4YN8aeA/jypPgW1hh/SiEIY6lNg9xOqIgox0m4sW1kMhGoNCygJ1Qvx8x33xSRD/AVtH+VtsCGn+LcQg=="],
+
+    "@pkmn/types": ["@pkmn/types@4.0.0", "", {}, "sha512-gR2s/pxJYEegek1TtsYCQupNR3d5hMlcJFsiD+2LyfKr4tc+gETTql47tWLX5mFSbPcbXh7f4+7txlMIDoZx/g=="],
+
+    "@pkmn/view": ["@pkmn/view@0.7.2", "", { "dependencies": { "@pkmn/protocol": "^0.7.2", "@pkmn/types": "^4.0.0" }, "bin": { "format-battle": "format-battle" } }, "sha512-SBaBIAuyJ/iGfYQxfzQ6jXv64Qz1/pIo5gjCXT9AfsErkHT27VwIhEEd2vUlD0bdfx802sPNvzHvLYJWMtss1w=="],
+
     "@pondwader/socks5-server": ["@pondwader/socks5-server@1.0.10", "https://registry.npmmirror.com/@pondwader/socks5-server/-/socks5-server-1.0.10.tgz", {}, "sha512-bQY06wzzR8D2+vVCUoBsr5QS2U6UgPUQRmErNwtsuI6vLcyRKkafjkr3KxbtGFf9aBBIV2mcvlsKD1UYaIV+sg=="],
 
     "@prisma/instrumentation": ["@prisma/instrumentation@7.6.0", "https://registry.npmmirror.com/@prisma/instrumentation/-/instrumentation-7.6.0.tgz", { "dependencies": { "@opentelemetry/instrumentation": "^0.207.0" }, "peerDependencies": { "@opentelemetry/api": "^1.8" } }, "sha512-ZPW2gRiwpPzEfgeZgaekhqXrbW+Y2RJKHVqUmlhZhKzRNCcvR6DykzylDrynpArKKRQtLxoZy36fK7U0p3pdgQ=="],
diff --git a/packages/pokemon/package.json b/packages/pokemon/package.json
index fb91826fe..96d105f33 100644
--- a/packages/pokemon/package.json
+++ b/packages/pokemon/package.json
@@ -5,5 +5,9 @@
   "type": "module",
   "main": "./src/index.ts",
   "types": "./src/index.ts",
-  "dependencies": {}
+  "dependencies": {
+    "@pkmn/client": "^0.7.2",
+    "@pkmn/protocol": "^0.7.2",
+    "@pkmn/view": "^0.7.2"
+  }
 }
diff --git a/packages/pokemon/src/battle/ai.ts b/packages/pokemon/src/battle/ai.ts
new file mode 100644
index 000000000..899b8f8e1
--- /dev/null
+++ b/packages/pokemon/src/battle/ai.ts
@@ -0,0 +1,13 @@
+import type { BattlePokemon } from './types'
+
+/**
+ * Simple AI: pick a random usable move.
+ */
+export function chooseAIMove(pokemon: BattlePokemon): number {
+	const usable = pokemon.moves
+		.map((m, i) => ({ move: m, index: i }))
+		.filter(({ move }) => move.pp > 0 && !move.disabled)
+
+	if (usable.length === 0) return 0 // Struggle
+	return usable[Math.floor(Math.random() * usable.length)]!.index
+}
diff --git a/packages/pokemon/src/battle/engine.ts b/packages/pokemon/src/battle/engine.ts
new file mode 100644
index 000000000..742cd8838
--- /dev/null
+++ b/packages/pokemon/src/battle/engine.ts
@@ -0,0 +1,285 @@
+import { Battle, Teams, toID } from '@pkmn/sim'
+import { Dex } from '@pkmn/sim'
+import type { Creature, SpeciesId } from '../types'
+import { TO_DEX_STAT, FROM_DEX_STAT } from '../data/pkmn'
+import { STAT_NAMES } from '../types'
+import type { BattleState, BattlePokemon, BattleEvent, BattleResult, PlayerAction, MoveOption, StatusCondition } from './types'
+import { chooseAIMove } from './ai'
+
+// ─── Adapter: Creature → Showdown Set ───
+
+function creatureToSetString(creature: Creature): string {
+	const species = Dex.species.get(creature.speciesId)
+	if (!species) throw new Error(`Species ${creature.speciesId} not found`)
+
+	const natureName = creature.nature.charAt(0).toUpperCase() + creature.nature.slice(1)
+	const abilityName = creature.ability ? (Dex.abilities.get(creature.ability)?.name ?? creature.ability) : ''
+
+	const moves = creature.moves
+		.filter(m => m.id)
+		.map(m => Dex.moves.get(m.id)?.name ?? m.id)
+
+	const ivs = STAT_NAMES.map(s => `${creature.iv[s]} ${TO_DEX_STAT[s].toUpperCase().replace('SPA', 'SpA').replace('SPD', 'SpD')}`).join(' / ')
+	const evs = STAT_NAMES.map(s => `${creature.ev[s]} ${TO_DEX_STAT[s].toUpperCase().replace('SPA', 'SpA').replace('SPD', 'SpD')}`).join(' / ')
+
+	const lines = [
+		species.name,
+		`Level: ${creature.level}`,
+		`Ability: ${abilityName}`,
+		`Nature: ${natureName}`,
+		`IVs: ${ivs}`,
+		`EVs: ${evs}`,
+	]
+	if (creature.heldItem) lines.push(`Item: ${Dex.items.get(creature.heldItem)?.name ?? creature.heldItem}`)
+	for (const move of moves) lines.push(`- ${move}`)
+
+	return lines.join('\n')
+}
+
+function wildPokemonToSetString(speciesId: SpeciesId, level: number): string {
+	const species = Dex.species.get(speciesId)
+	if (!species) throw new Error(`Species ${speciesId} not found`)
+	const ability = species.abilities['0'] ?? ''
+	// Get first 4 level-up moves (from species data)
+	const moves = getSpeciesMoves(speciesId, level)
+	return [species.name, `Level: ${level}`, `Ability: ${ability}`, ...moves.map(m => `- ${m}`)].join('\n')
+}
+
+function getSpeciesMoves(speciesId: string, level: number): string[] {
+	// Use @pkmn/sim move pool - get natural level-up moves
+	// This is a simplified approach for the sim
+	const species = Dex.species.get(speciesId)
+	if (!species) return ['Tackle']
+	// For sim battles, just return basic moves
+	return ['Tackle', 'Splash']
+}
+
+// ─── State Projection ───
+
+function projectPokemon(pkm: any): BattlePokemon {
+	if (!pkm) throw new Error('No active pokemon')
+	const species = pkm.species
+	const hp = pkm.hp ?? 0
+	const maxHp = pkm.maxhp ?? 1
+
+	return {
+		id: pkm.name, // sim doesn't store our UUID, use name as temp id
+		speciesId: toID(species.name) as SpeciesId,
+		name: species.name,
+		level: pkm.level,
+		hp,
+		maxHp,
+		types: species.types?.map((t: string) => t.toLowerCase()) ?? [],
+		moves: (pkm.moveSlots ?? pkm.baseMoveset ?? []).filter(Boolean).map((m: any) => ({
+			id: toID(m.name ?? m),
+			name: m.name ?? m,
+			type: m.type ?? 'Normal',
+			pp: m.pp ?? 0,
+			maxPp: m.maxPp ?? m.pp ?? 0,
+			disabled: m.disabled ?? false,
+		})),
+		ability: pkm.ability ?? '',
+		heldItem: pkm.item ?? null,
+		status: mapStatus(pkm.status),
+		statStages: projectBoosts(pkm.boosts),
+	}
+}
+
+function mapStatus(status: string): StatusCondition {
+	if (!status) return 'none'
+	const s = status.toLowerCase()
+	if (s === 'psn') return 'poison'
+	if (s === 'tox') return 'bad_poison'
+	if (s === 'brn') return 'burn'
+	if (s === 'par') return 'paralysis'
+	if (s === 'frz') return 'freeze'
+	if (s === 'slp') return 'sleep'
+	return 'none'
+}
+
+function projectBoosts(boosts: Record<string, number> | undefined): Record<string, number> {
+	if (!boosts) return {}
+	const result: Record<string, number> = {}
+	for (const [k, v] of Object.entries(boosts)) {
+		const mapped = FROM_DEX_STAT[k]
+		if (mapped) result[mapped] = v
+		else result[k] = v
+	}
+	return result
+}
+
+// ─── Log Parsing ───
+
+function parseLogToEvents(log: string[]): BattleEvent[] {
+	const events: BattleEvent[] = []
+	for (const line of log) {
+		if (line.startsWith('|move|')) {
+			const parts = line.split('|')
+			const side = parts[2]?.startsWith('p1a') ? 'player' : 'opponent'
+			const moveName = parts[3]
+			events.push({ type: 'move', side, move: moveName, user: parts[2] })
+		} else if (line.startsWith('|-damage|')) {
+			const parts = line.split('|')
+			const side = parts[2]?.startsWith('p1a') ? 'player' : 'opponent'
+			const hpStr = parts[3] // e.g. "16/20" or "16/20[1]"
+			const [cur, max] = parseHpString(hpStr)
+			events.push({ type: 'damage', side, amount: 0, percentage: Math.round((1 - cur / max) * 100) })
+		} else if (line.startsWith('|-heal|')) {
+			const parts = line.split('|')
+			const side = parts[2]?.startsWith('p1a') ? 'player' : 'opponent'
+			const hpStr = parts[3]
+			const [cur, max] = parseHpString(hpStr)
+			events.push({ type: 'heal', side, amount: 0, percentage: Math.round(cur / max * 100) })
+		} else if (line.startsWith('|faint|')) {
+			const parts = line.split('|')
+			const side = parts[2]?.startsWith('p1a') ? 'player' : 'opponent'
+			events.push({ type: 'faint', side, speciesId: toID(parts[2]?.split(': ')?.[1] ?? '') })
+		} else if (line.startsWith('|switch|')) {
+			const parts = line.split('|')
+			const side = parts[2]?.startsWith('p1a') ? 'player' : 'opponent'
+			const speciesPart = parts[3]?.split(',')[0]?.split(': ')
+			events.push({ type: 'switch', side, speciesId: toID(speciesPart?.[1] ?? ''), name: speciesPart?.[1] ?? '' })
+		} else if (line.startsWith('|-supereffective|')) {
+			events.push({ type: 'effectiveness', multiplier: 2 })
+		} else if (line.startsWith('|-resisted|')) {
+			events.push({ type: 'effectiveness', multiplier: 0.5 })
+		} else if (line.startsWith('|-crit|')) {
+			events.push({ type: 'crit' })
+		} else if (line.startsWith('|-miss|')) {
+			const parts = line.split('|')
+			const side = parts[2]?.startsWith('p1a') ? 'player' : 'opponent'
+			events.push({ type: 'miss', side } as any)
+		} else if (line.startsWith('|-status|')) {
+			const parts = line.split('|')
+			const side = parts[2]?.startsWith('p1a') ? 'player' : 'opponent'
+			events.push({ type: 'status', side, status: mapStatus(parts[3]) })
+		} else if (line.startsWith('|-boost|') || line.startsWith('|-unboost|')) {
+			const parts = line.split('|')
+			const side = parts[2]?.startsWith('p1a') ? 'player' : 'opponent'
+			const stages = line.startsWith('|-boost|') ? parseInt(parts[4]) : -parseInt(parts[4])
+			events.push({ type: 'statChange', side, stat: parts[3], stages })
+		} else if (line.startsWith('|-ability|')) {
+			const parts = line.split('|')
+			const side = parts[2]?.startsWith('p1a') ? 'player' : 'opponent'
+			events.push({ type: 'ability', side, ability: parts[3] })
+		} else if (line.startsWith('|turn|')) {
+			events.push({ type: 'turn', number: parseInt(line.split('|')[2]) })
+		}
+	}
+	return events
+}
+
+function parseHpString(hpStr: string): [number, number] {
+	if (!hpStr) return [0, 1]
+	// Remove status suffix like "[1]"
+	const clean = hpStr.replace(/\[.*\]/, '')
+	const parts = clean.split('/')
+	if (parts.length !== 2) return [0, 1]
+	return [parseInt(parts[0]) || 0, parseInt(parts[1]) || 1]
+}
+
+// ─── Engine ───
+
+export type BattleInit = {
+	battle: any  // @pkmn/sim Battle instance
+	state: BattleState
+}
+
+export function createBattle(
+	partyCreatures: Creature[],
+	opponentSpeciesId: SpeciesId,
+	opponentLevel: number,
+	_bagItems?: { id: string; count: number }[],
+): BattleInit {
+	const p1Sets = partyCreatures.map(c => creatureToSetString(c))
+	const p2Set = wildPokemonToSetString(opponentSpeciesId, opponentLevel)
+
+	const p1Team = Teams.import(p1Sets.join('\n\n'))
+	const p2Team = Teams.import(p2Set)
+
+	// Create battle
+	const battle = new Battle({
+		formatid: 'gen9customgame' as any,
+		p1: { name: 'Player', team: p1Team },
+		p2: { name: 'Opponent', team: p2Team },
+	})
+
+	// Handle team preview → auto-select leads
+	battle.makeChoices('team 1', 'team 1')
+
+	// Project initial state
+	const state = projectState(battle, _bagItems)
+	return { battle, state }
+}
+
+export function executeTurn(
+	battleInit: BattleInit,
+	action: PlayerAction,
+): BattleState {
+	const { battle } = battleInit
+	const prevLogLen = battle.log.length
+
+	// Build choice string
+	let p1Choice: string
+	switch (action.type) {
+		case 'move':
+			p1Choice = `move ${action.moveIndex + 1}`
+			break
+		case 'switch':
+			p1Choice = `switch ${action.creatureId}`
+			break
+		case 'item':
+			p1Choice = 'move 1' // Items handled via settlement
+			break
+		default:
+			p1Choice = 'move 1'
+	}
+
+	// AI choice
+	const aiPokemon = projectPokemon(battle.p2.active[0])
+	const aiMoveIndex = chooseAIMove(aiPokemon)
+	const p2Choice = `move ${aiMoveIndex + 1}`
+
+	// Execute
+	battle.makeChoices(p1Choice, p2Choice)
+
+	// Parse new log entries
+	const newLog = battle.log.slice(prevLogLen)
+	const newEvents = parseLogToEvents(newLog)
+
+	// Project new state
+	const state = projectState(battle, battleInit.state.usableItems)
+	state.events = [...battleInit.state.events, ...newEvents]
+
+	// Check for battle end
+	if (battle.ended) {
+		state.finished = true
+		const winner = battle.winner === 'Player' ? 'player' : 'opponent'
+		state.result = {
+			winner,
+			turns: state.turn,
+			xpGained: 0, // calculated in settlement
+			evGained: { hp: 0, attack: 0, defense: 0, spAtk: 0, spDef: 0, speed: 0 },
+			participantIds: [],
+		}
+	}
+
+	battleInit.state = state
+	return state
+}
+
+function projectState(battle: any, bagItems?: { id: string; count: number }[]): BattleState {
+	const p1 = battle.p1
+	const p2 = battle.p2
+
+	return {
+		playerPokemon: projectPokemon(p1.active[0]),
+		opponentPokemon: projectPokemon(p2.active[0]),
+		playerParty: p1.pokemon.map((p: any) => projectPokemon(p)),
+		opponentParty: p2.pokemon.map((p: any) => projectPokemon(p)),
+		turn: battle.turn ?? 1,
+		events: [],
+		finished: battle.ended,
+		usableItems: bagItems?.filter(i => i.count > 0).map(i => ({ id: i.id, name: i.id, count: i.count })) ?? [],
+	}
+}
diff --git a/packages/pokemon/src/battle/index.ts b/packages/pokemon/src/battle/index.ts
new file mode 100644
index 000000000..807204d59
--- /dev/null
+++ b/packages/pokemon/src/battle/index.ts
@@ -0,0 +1,4 @@
+export type { BattleState, BattlePokemon, BattleEvent, BattleResult, PlayerAction, MoveOption, StatusCondition } from './types'
+export { createBattle, executeTurn, type BattleInit } from './engine'
+export { settleBattle, applyMoveLearn, applyEvolution } from './settlement'
+export { chooseAIMove } from './ai'
diff --git a/packages/pokemon/src/battle/settlement.ts b/packages/pokemon/src/battle/settlement.ts
new file mode 100644
index 000000000..63cf22517
--- /dev/null
+++ b/packages/pokemon/src/battle/settlement.ts
@@ -0,0 +1,167 @@
+import type { Creature, StatName, SpeciesId } from '../types'
+import { STAT_NAMES } from '../types'
+import { TO_DEX_STAT } from '../data/pkmn'
+import type { BattleResult } from './types'
+import type { BuddyData } from '../types'
+import { addItemToBag, removeItemFromBag } from '../core/storage'
+import { xpForLevel, levelFromXp } from '../data/xpTable'
+import { getSpeciesData } from '../data/species'
+import { Dex } from '@pkmn/sim'
+
+/**
+ * Settle battle results: XP, EV, level ups, move learning, evolution detection.
+ */
+export function settleBattle(
+	data: BuddyData,
+	result: BattleResult,
+	opponentSpeciesId: SpeciesId,
+	opponentLevel: number,
+): {
+	data: BuddyData
+	learnableMoves: { creatureId: string; moveId: string; moveName: string }[]
+	pendingEvolutions: { creatureId: string; from: SpeciesId; to: SpeciesId }[]
+} {
+	if (result.winner !== 'player') {
+		return { data, learnableMoves: [], pendingEvolutions: [] }
+	}
+
+	// Calculate XP reward (simplified: base XP from species)
+	const species = Dex.species.get(opponentSpeciesId)
+	const baseXp = (species?.baseStats?.hp ?? 50) * opponentLevel / 7
+	const xpGained = Math.max(1, Math.floor(baseXp))
+
+	// Calculate EV reward
+	const evGained: Record<StatName, number> = { hp: 0, attack: 0, defense: 0, spAtk: 0, spDef: 0, speed: 0 }
+	const evYield = getEvYield(opponentSpeciesId)
+	for (const stat of STAT_NAMES) {
+		evGained[stat] = evYield[TO_DEX_STAT[stat]] ?? 0
+	}
+
+	// Award XP/EV to participant creatures
+	const learnableMoves: { creatureId: string; moveId: string; moveName: string }[] = []
+	const pendingEvolutions: { creatureId: string; from: SpeciesId; to: SpeciesId }[] = []
+	const participantIds = new Set(result.participantIds.length > 0 ? result.participantIds : data.party.filter(Boolean))
+
+	const updatedCreatures = data.creatures.map(creature => {
+		if (!participantIds.has(creature.id)) return creature
+
+		// Award EVs (capped)
+		const newEv = { ...creature.ev }
+		let totalEV = STAT_NAMES.reduce((sum, s) => sum + newEv[s], 0)
+		for (const stat of STAT_NAMES) {
+			if (totalEV >= 510) break
+			const gain = Math.min(evGained[stat], 252 - newEv[stat], 510 - totalEV)
+			newEv[stat] += gain
+			totalEV += gain
+		}
+
+		// Award XP
+		const oldLevel = creature.level
+		const newTotalXp = creature.totalXp + xpGained
+		const species = getSpeciesData(creature.speciesId)
+		const newLevel = Math.min(100, levelFromXp(newTotalXp, species.growthRate))
+
+		// Detect new learnable moves (async in real code, but for settlement we check synchronously)
+		// This will be handled at the UI level with getNewLearnableMoves
+
+		// Detect evolution
+		if (newLevel > oldLevel) {
+			const species = Dex.species.get(creature.speciesId)
+			if (species?.evos?.length) {
+				const targetId = species.evos[0]!.toLowerCase()
+				const target = Dex.species.get(targetId)
+				if (target?.evoLevel && newLevel >= target.evoLevel) {
+					pendingEvolutions.push({
+						creatureId: creature.id,
+						from: creature.speciesId,
+						to: targetId as SpeciesId,
+					})
+				}
+			}
+		}
+
+		return {
+			...creature,
+			level: newLevel,
+			totalXp: newTotalXp,
+			ev: newEv,
+		}
+	})
+
+	// Update data
+	const updatedData: BuddyData = {
+		...data,
+		creatures: updatedCreatures,
+		stats: {
+			...data.stats,
+			battlesWon: data.stats.battlesWon + (result.winner === 'player' ? 1 : 0),
+			battlesLost: data.stats.battlesLost + (result.winner !== 'player' ? 1 : 0),
+		},
+	}
+
+	return { data: updatedData, learnableMoves, pendingEvolutions }
+}
+
+/**
+ * Apply move learning - replace a move at the given index.
+ */
+export function applyMoveLearn(
+	data: BuddyData,
+	creatureId: string,
+	moveId: string,
+	replaceIndex: number,
+): BuddyData {
+	return {
+		...data,
+		creatures: data.creatures.map(c => {
+			if (c.id !== creatureId) return c
+			const dexMove = Dex.moves.get(moveId)
+			const newMoves = [...c.moves] as typeof c.moves
+			newMoves[replaceIndex] = {
+				id: moveId,
+				pp: dexMove?.pp ?? 10,
+				maxPp: dexMove?.pp ?? 10,
+			}
+			return { ...c, moves: newMoves as typeof c.moves }
+		}),
+	}
+}
+
+/**
+ * Apply evolution to a creature.
+ */
+export function applyEvolution(
+	data: BuddyData,
+	creatureId: string,
+	newSpeciesId: SpeciesId,
+): BuddyData {
+	return {
+		...data,
+		creatures: data.creatures.map(c =>
+			c.id === creatureId
+				? { ...c, speciesId: newSpeciesId, friendship: Math.min(255, c.friendship + 10) }
+				: c,
+		),
+		stats: {
+			...data.stats,
+			totalEvolutions: data.stats.totalEvolutions + 1,
+		},
+	}
+}
+
+function getEvYield(speciesId: string): Record<string, number> {
+	// @pkmn/sim Dex.species doesn't have evs field
+	// Use baseStats as proxy: highest base stat gets 1-2 EVs
+	const species = Dex.species.get(speciesId)
+	if (!species?.baseStats) return {}
+	const stats = species.baseStats as Record<string, number>
+	const entries = Object.entries(stats)
+	if (entries.length === 0) return {}
+	// Sort by value descending, give 1-2 EV to top stats
+	entries.sort((a, b) => b[1] - a[1])
+	const result: Record<string, number> = {}
+	// Top stat gets 2 EVs, second gets 1
+	if (entries[0]) result[entries[0][0]] = 2
+	if (entries[1]) result[entries[1][0]] = 1
+	return result
+}
diff --git a/packages/pokemon/src/battle/types.ts b/packages/pokemon/src/battle/types.ts
new file mode 100644
index 000000000..557a0a395
--- /dev/null
+++ b/packages/pokemon/src/battle/types.ts
@@ -0,0 +1,68 @@
+import type { StatName, SpeciesId } from '../types'
+
+export type StatusCondition = 'poison' | 'bad_poison' | 'burn' | 'paralysis' | 'freeze' | 'sleep' | 'none'
+
+export type BattlePokemon = {
+	id: string                        // creature ID
+	speciesId: SpeciesId
+	name: string
+	level: number
+	hp: number                        // current HP in battle
+	maxHp: number
+	types: string[]
+	moves: MoveOption[]
+	ability: string
+	heldItem: string | null
+	status: StatusCondition
+	statStages: Record<string, number> // -6 to +6
+}
+
+export type MoveOption = {
+	id: string
+	name: string
+	type: string
+	pp: number
+	maxPp: number
+	disabled: boolean
+}
+
+export type PlayerAction =
+	| { type: 'move'; moveIndex: number }
+	| { type: 'switch'; creatureId: string }
+	| { type: 'item'; itemId: string }
+
+export type BattleEvent =
+	| { type: 'move'; side: 'player' | 'opponent'; move: string; user: string }
+	| { type: 'damage'; side: 'player' | 'opponent'; amount: number; percentage: number }
+	| { type: 'heal'; side: 'player' | 'opponent'; amount: number; percentage: number }
+	| { type: 'faint'; side: 'player' | 'opponent'; speciesId: string }
+	| { type: 'switch'; side: 'player' | 'opponent'; speciesId: string; name: string }
+	| { type: 'effectiveness'; multiplier: number }
+	| { type: 'crit' }
+	| { type: 'miss' }
+	| { type: 'status'; side: 'player' | 'opponent'; status: StatusCondition }
+	| { type: 'statChange'; side: 'player' | 'opponent'; stat: string; stages: number }
+	| { type: 'ability'; side: 'player' | 'opponent'; ability: string }
+	| { type: 'item'; side: 'player' | 'opponent'; item: string }
+	| { type: 'fail'; reason: string }
+	| { type: 'turn'; number: number }
+
+export type BattleResult = {
+	winner: 'player' | 'opponent'
+	turns: number
+	xpGained: number
+	evGained: Record<StatName, number>
+	participantIds: string[]
+}
+
+export type BattleState = {
+	playerPokemon: BattlePokemon
+	opponentPokemon: BattlePokemon
+	playerParty: BattlePokemon[]
+	opponentParty: BattlePokemon[]
+	turn: number
+	events: BattleEvent[]
+	finished: boolean
+	result?: BattleResult
+	usableItems: { id: string; name: string; count: number }[]
+}
diff --git a/packages/pokemon/src/index.ts b/packages/pokemon/src/index.ts
index 7967d50af..5465f0e0c 100644
--- a/packages/pokemon/src/index.ts
+++ b/packages/pokemon/src/index.ts
@@ -36,6 +36,12 @@ export { getNextEvolution, EVOLUTION_CHAINS } from './data/evolution'
 export { getDefaultMoveset, getDefaultAbility, getNewLearnableMoves } from './data/learnsets'
 export { FROM_DEX_STAT, TO_DEX_STAT } from './data/pkmn'
 
+// Battle
+export type { BattleState, BattlePokemon, BattleEvent, BattleResult, PlayerAction, MoveOption, StatusCondition } from './battle/types'
+export { createBattle, executeTurn, type BattleInit } from './battle/engine'
+export { settleBattle, applyMoveLearn, applyEvolution } from './battle/settlement'
+export { chooseAIMove } from './battle/ai'
+
 // Core
 export { generateCreature, calculateStats, getCreatureName, recalculateLevel, getActiveCreature, getTotalEV } from './core/creature'
 export { determineGender, getGenderSymbol } from './core/gender'