diff --git a/src/Domain/UnitState.php b/src/Domain/UnitState.php
index 76f8a1a..5ae486c 100644
--- a/src/Domain/UnitState.php
+++ b/src/Domain/UnitState.php
@@ -8,6 +8,7 @@ use InvalidArgumentException;
 
 final readonly class UnitState
 {
+    /** @param list<string> $abilities */
     public function __construct(
         public string $id,
         public string $teamId,
@@ -19,6 +20,10 @@ final readonly class UnitState
         public int $speed,
         public int $actionsRemaining,
         public bool $hasAttacked = false,
+        public Archetype $archetype = Archetype::Defender,
+        public array $abilities = [],
+        public int $attackBonus = 0,
+        public bool $hasUsedAbility = false,
     ) {
         if ($id === '') {
             throw new InvalidArgumentException('Unit id cannot be empty.');
@@ -47,6 +52,21 @@ final readonly class UnitState
         if ($actionsRemaining < 0 || $actionsRemaining > 2) {
             throw new InvalidArgumentException('Unit actions remaining must be between 0 and 2.');
         }
+
+        if ($attackBonus < 0) {
+            throw new InvalidArgumentException('Unit attack bonus cannot be negative.');
+        }
+
+        if (!self::isList($abilities)) {
+            throw new InvalidArgumentException('Unit abilities must be a list.');
+        }
+
+        foreach ($abilities as $ability) {
+            // @phpstan-ignore function.alreadyNarrowedType (Runtime guard: PHPDoc is not a runtime contract for JSON-sourced arrays in Plan 4.)
+            if (!is_string($ability) || $ability === '') {
+                throw new InvalidArgumentException('Unit abilities must be non-empty strings.');
+            }
+        }
     }
 
     public function isDefeated(): bool
@@ -54,6 +74,12 @@ final readonly class UnitState
         return $this->health === 0;
     }
 
+    /** @return list<string> */
+    public function allowedAbilities(): array
+    {
+        return ArchetypeCatalog::templates()[$this->archetype->value]->allowedAbilities;
+    }
+
     public function moveTo(Position $position): self
     {
         return $this->copy(position: $position);
@@ -68,6 +94,19 @@ final readonly class UnitState
         return $this->copy(actionsRemaining: $this->actionsRemaining - 1);
     }
 
+    public function spendAbility(): self
+    {
+        if ($this->hasUsedAbility) {
+            throw new InvalidArgumentException('Unit has already used an ability this turn.');
+        }
+
+        if ($this->actionsRemaining === 0) {
+            throw new InvalidArgumentException('Unit has no actions remaining.');
+        }
+
+        return $this->copy(actionsRemaining: $this->actionsRemaining - 1, hasUsedAbility: true);
+    }
+
     public function takeDamage(int $damage): self
     {
         return $this->copy(health: max(0, $this->health - max(0, $damage)));
@@ -78,13 +117,27 @@ final readonly class UnitState
         return $this->copy(hasAttacked: true);
     }
 
+    public function withAttackBonus(int $bonus): self
+    {
+        if ($bonus < 0) {
+            throw new InvalidArgumentException('Attack bonus cannot be negative.');
+        }
+
+        return $this->copy(attackBonus: $bonus);
+    }
+
     public function startTurn(): self
     {
         if ($this->isDefeated()) {
             return $this;
         }
 
-        return $this->copy(actionsRemaining: 2, hasAttacked: false);
+        return $this->copy(
+            actionsRemaining: 2,
+            hasAttacked: false,
+            attackBonus: 0,
+            hasUsedAbility: false,
+        );
     }
 
     private function copy(
@@ -92,6 +145,8 @@ final readonly class UnitState
         ?int $health = null,
         ?int $actionsRemaining = null,
         ?bool $hasAttacked = null,
+        ?int $attackBonus = null,
+        ?bool $hasUsedAbility = null,
     ): self {
         return new self(
             $this->id,
@@ -104,6 +159,15 @@ final readonly class UnitState
             $this->speed,
             $actionsRemaining ?? $this->actionsRemaining,
             $hasAttacked ?? $this->hasAttacked,
+            $this->archetype,
+            $this->abilities,
+            $attackBonus ?? $this->attackBonus,
+            $hasUsedAbility ?? $this->hasUsedAbility,
         );
     }
+
+    private static function isList(mixed $value): bool
+    {
+        return is_array($value) && array_is_list($value);
+    }
 }
diff --git a/tests/Unit/Domain/UnitStateTest.php b/tests/Unit/Domain/UnitStateTest.php
index 0bf48f9..c28072c 100644
--- a/tests/Unit/Domain/UnitStateTest.php
+++ b/tests/Unit/Domain/UnitStateTest.php
@@ -132,10 +132,109 @@ final class UnitStateTest extends TestCase
         self::assertSame($unit, $unit->startTurn());
     }
 
+    public function testItCarriesArchetypeAbilitiesAndBonus(): void
+    {
+        $unit = new UnitState(
+            id: 'unit-1',
+            teamId: 'alpha',
+            position: new Position(0, 0),
+            maxHealth: 10,
+            health: 10,
+            attack: 4,
+            defense: 2,
+            speed: 4,
+            actionsRemaining: 2,
+            hasAttacked: false,
+            archetype: \BattleForge\Domain\Archetype::Support,
+            abilities: ['heal', 'buff'],
+            attackBonus: 2,
+            hasUsedAbility: false,
+        );
+
+        self::assertSame(\BattleForge\Domain\Archetype::Support, $unit->archetype);
+        self::assertSame(['heal', 'buff'], $unit->abilities);
+        self::assertSame(2, $unit->attackBonus);
+        self::assertFalse($unit->hasUsedAbility);
+    }
+
+    public function testItRejectsEmptyStringAbilities(): void
+    {
+        $this->expectException(InvalidArgumentException::class);
+        $this->expectExceptionMessage('Unit abilities must be non-empty strings.');
+
+        new UnitState(
+            id: 'unit-1',
+            teamId: 'alpha',
+            position: new Position(0, 0),
+            maxHealth: 10,
+            health: 10,
+            attack: 4,
+            defense: 2,
+            speed: 4,
+            actionsRemaining: 2,
+            hasAttacked: false,
+            archetype: \BattleForge\Domain\Archetype::Defender,
+            abilities: [''],
+        );
+    }
+
+    public function testItExposesAllowedAbilitiesFromTheArchetypeCatalog(): void
+    {
+        $unit = $this->unit();
+
+        self::assertSame(
+            \BattleForge\Domain\ArchetypeCatalog::templates()[$unit->archetype->value]->allowedAbilities,
+            $unit->allowedAbilities(),
+        );
+    }
+
+    public function testWithAttackBonusReturnsAChangedCopyAndRejectsNegativeBonus(): void
+    {
+        $unit = $this->unit();
+        $buffed = $unit->withAttackBonus(3);
+
+        self::assertNotSame($unit, $buffed);
+        self::assertSame(0, $unit->attackBonus);
+        self::assertSame(3, $buffed->attackBonus);
+
+        $this->expectException(\InvalidArgumentException::class);
+        $unit->withAttackBonus(-1);
+    }
+
+    public function testSpendAbilityMarksAndConsumesOneActionButNotTwo(): void
+    {
+        $unit = $this->unit();
+        $spent = $unit->spendAbility();
+
+        self::assertSame(1, $spent->actionsRemaining);
+        self::assertTrue($spent->hasUsedAbility);
+    }
+
+    public function testSpendAbilityRejectsAUnitThatAlreadyUsedAnAbility(): void
+    {
+        $unit = $this->unit(hasUsedAbility: true);
+
+        $this->expectException(\InvalidArgumentException::class);
+        $unit->spendAbility();
+    }
+
+    public function testStartTurnClearsAttackBonusAndAbilityUse(): void
+    {
+        $unit = $this->unit(actionsRemaining: 0, hasAttacked: true, attackBonus: 3, hasUsedAbility: true);
+        $started = $unit->startTurn();
+
+        self::assertSame(2, $started->actionsRemaining);
+        self::assertFalse($started->hasAttacked);
+        self::assertSame(0, $started->attackBonus);
+        self::assertFalse($started->hasUsedAbility);
+    }
+
     private function unit(
         int $health = 10,
         int $actionsRemaining = 2,
         bool $hasAttacked = false,
+        int $attackBonus = 0,
+        bool $hasUsedAbility = false,
     ): UnitState {
         return new UnitState(
             'unit-1',
@@ -148,6 +247,10 @@ final class UnitStateTest extends TestCase
             4,
             $actionsRemaining,
             $hasAttacked,
+            archetype: \BattleForge\Domain\Archetype::Defender,
+            abilities: [],
+            attackBonus: $attackBonus,
+            hasUsedAbility: $hasUsedAbility,
         );
     }
 }