diff --git a/Assets/Battle/BaseCard.cs b/Assets/Battle/BaseCard.cs
index d9caf9c..3faaf08 100644
--- a/Assets/Battle/BaseCard.cs
+++ b/Assets/Battle/BaseCard.cs
@@ -18,6 +18,7 @@ public abstract class BaseCard
         this.effectText = effectText;
     }
 
+    public BattleParticipant Owner {get => this.owner;}
     public string GetDisplayName() {return this.displayName;}
     public int GetCost() {return this.cost;}
     public string GetDisplayType() {
diff --git a/Assets/Battle/BattleController.cs b/Assets/Battle/BattleController.cs
index 3158af3..ec3a997 100644
--- a/Assets/Battle/BattleController.cs
+++ b/Assets/Battle/BattleController.cs
@@ -62,6 +62,7 @@ public class BattleController : MonoBehaviour, IBattleEffectApplier, IBattleEffe
             BattleParticipantSprite bps = heroSprites[i].AddComponent<BattleParticipantSprite>();
             bps.Init(battlePlayerControls, heroes[i]);
             bps.OnSpriteClicked += battlePlayerControls.NotifyParticipantSpriteClicked;
+            heroes[i].OnDeath += bps.NotifyDeath;
 
             heroUIs[i] = (HeroInfoUI) Instantiate(heroUIPrefab.gameObject, uiCanvas.transform).GetComponent(typeof(HeroInfoUI));
             heroUIs[i].Init(heroSprites[i], heroes[i]);
@@ -82,6 +83,7 @@ public class BattleController : MonoBehaviour, IBattleEffectApplier, IBattleEffe
             BattleParticipantSprite bps = monsterSprites[i].AddComponent<BattleParticipantSprite>();
             bps.Init(battlePlayerControls, monsters[i]);
             bps.OnSpriteClicked += battlePlayerControls.NotifyParticipantSpriteClicked;
+            monsters[i].OnDeath += bps.NotifyDeath;
 
             monsterUIs[i] = (HeroInfoUI) Instantiate(heroUIPrefab.gameObject, uiCanvas.transform).GetComponent(typeof(HeroInfoUI));
             monsterUIs[i].Init(monsterSprites[i], monsters[i]);
@@ -237,11 +239,11 @@ public class BattleController : MonoBehaviour, IBattleEffectApplier, IBattleEffe
     }
 
     public bool CanUseHeroCard(HeroCard card) {
-        return this.heroTurn && this.heroEnergy.CanPayForCard(card);
+        return this.heroTurn && card.Owner.IsAlive() && this.heroEnergy.CanPayForCard(card);
     }
 
     public bool CanUseMonsterCard(MonsterCard card) {
-        return !this.heroTurn && this.monsterEnergy.CanPayForCard(card);
+        return !this.heroTurn && card.Owner.IsAlive() && this.monsterEnergy.CanPayForCard(card);
     }
 
     public BattleDeck<HeroCard> GetHeroDeck() {
diff --git a/Assets/Battle/BattleParticipant.cs b/Assets/Battle/BattleParticipant.cs
index 1e66f99..c296f9f 100644
--- a/Assets/Battle/BattleParticipant.cs
+++ b/Assets/Battle/BattleParticipant.cs
@@ -5,11 +5,15 @@ using UnityEngine;
 
 public class BattleParticipant
 {
+    public delegate void DeathAction(BattleParticipant participant);
+    public event DeathAction OnDeath;
+
     protected bool isHero;
     protected string displayName;
     protected int hp;
     protected int maxHP;
     protected int block;
+    protected bool dead;
 
     public BattleParticipant(bool isHero) {
         this.isHero = isHero;
@@ -32,7 +36,7 @@ public class BattleParticipant
     }
 
     public bool IsAlive() {
-        return this.hp > 0;
+        return !this.dead;
     }
 
     public int DealDamage(int damage) {
@@ -43,6 +47,10 @@ public class BattleParticipant
         }
         damage = Math.Min(this.hp, damage);
         this.hp -= damage;
+        if (this.hp <= 0) {
+            this.dead = true;
+            TriggerOnDeath();
+        }
         return damage;
     }
 
@@ -78,4 +86,10 @@ public class BattleParticipant
             this.hp += amount;
         }
     }
+
+    private void TriggerOnDeath() {
+        if (this.OnDeath != null) {
+            this.OnDeath(this);
+        }
+    }
 }
diff --git a/Assets/Battle/BattleParticipantSprite.cs b/Assets/Battle/BattleParticipantSprite.cs
index b306630..3326124 100644
--- a/Assets/Battle/BattleParticipantSprite.cs
+++ b/Assets/Battle/BattleParticipantSprite.cs
@@ -9,10 +9,12 @@ public class BattleParticipantSprite : MonoBehaviour
 
     private BattlePlayerControls playerControls;
     private BattleParticipant participant;
+    private bool removedFromBattle;
 
     public void Init(BattlePlayerControls playerControls, BattleParticipant participant) {
         this.playerControls = playerControls;
         this.participant = participant;
+        this.removedFromBattle = false;
     }
 
     // Start is called before the first frame update
@@ -22,20 +24,22 @@ public class BattleParticipantSprite : MonoBehaviour
 
     // Update is called once per frame
     void Update() {
-        if (colorChanged && !this.playerControls.CouldTarget(participant)) {
+        if (this.colorChanged && !this.playerControls.CouldTarget(participant)) {
             OnMouseExit();
         }
     }
 
     void OnMouseDown() {
-        OnSpriteClicked(participant);
+        if (!this.removedFromBattle) {
+            OnSpriteClicked(participant);
+        }
     }
 
     private Color savedColor;
     private bool colorChanged;
 
     void OnMouseEnter() {
-        if (this.playerControls.CouldTarget(participant)) {
+        if (!this.removedFromBattle && this.playerControls.CouldTarget(participant)) {
             SpriteRenderer sprite = GetComponent<SpriteRenderer>();
             this.savedColor = sprite.color;
             sprite.color = Color.Lerp(this.savedColor, Color.white, .5f);
@@ -50,4 +54,19 @@ public class BattleParticipantSprite : MonoBehaviour
             this.colorChanged = false;
         }
     }
+
+    public void NotifyDeath(BattleParticipant deadParticipant) {
+        if (deadParticipant != this.participant) {
+            throw new System.InvalidOperationException(
+                "BattleParticipantSprite received NotifyDeath from another battle participant.");
+        }
+        
+        if (!this.removedFromBattle) {
+            SpriteRenderer sprite = GetComponent<SpriteRenderer>();
+            sprite.enabled = false;
+            BoxCollider2D collider = GetComponent<BoxCollider2D>();
+            collider.enabled = false;
+            this.removedFromBattle = true;
+        }
+    }
 }
diff --git a/TODO.txt b/TODO.txt
index 0d49c25..f30f8a5 100644
--- a/TODO.txt
+++ b/TODO.txt
@@ -1,3 +1,3 @@
-- Make battle end
-- Do not allow dead heroes to act
+- Make battle end as state based effect
+- Check death as state based effect
 - Rename CardId to HCardId
\ No newline at end of file