diff --git a/Java-Knight/src/main/java/org/project/entity/Entity.java b/Java-Knight/src/main/java/org/project/entity/Entity.java
index 8225555..3e59401 100644
--- a/Java-Knight/src/main/java/org/project/entity/Entity.java
+++ b/Java-Knight/src/main/java/org/project/entity/Entity.java
@@ -1,49 +1,123 @@
 package org.project.entity;
 
-import org.project.item.Accessory.Custom;
+import org.project.Interface.IDamageable;
+import org.project.Interface.IDefendable;
+import org.project.Interface.IDefender;
+import org.project.Interface.IHealable;
+import org.project.constants.gameConstant.AttackPowerUp;
+import org.project.constants.gameConstant.EntityState;
+import org.project.constants.gameConstant.ItemClass;
+import org.project.constants.gameConstant.ItemClassExt;
+import org.project.item.Accessory.Costume;
 import org.project.item.Accessory.Shield;
 import org.project.item.Accessory.Weapon;
 import org.project.item.Item;
+import org.project.item.SellableItem;
 
 import java.util.ArrayList;
 
-public abstract class Entity {
+public abstract class Entity implements IDamageable, IHealable, IDefendable {
 
     public int MaxHealth;
-    public long Money;
+    public int Health;
+    private long Money;
     private int BaseDamage;
+    private EntityState State;
     public Weapon Weapon;
     public Shield Shield;
     public Costume Costume;
     public ArrayList<Item> Inventory;
 
-    public int getBaseDamage() {
-        return BaseDamage;
+    public EntityState GetState() { return State; }
+
+    public int GetBaseDamage() { return BaseDamage; }
+
+    public long GetMoney() { return Money; }
+
+    public ArrayList<Item> GetInventory() { return Inventory; }
+
+    public ArrayList<Item> GetInventoryByClass(ItemClass itemClass) {
+        ArrayList<Item> result = new ArrayList<>();
+
+        for (Item item : Inventory) {
+            if (ItemClassExt.Matches(itemClass, item)) {
+                result.add(item);
+            }
+        }
+
+        return result;
     }
 
-    public void setBaseDamage(int baseDamage) {
-        BaseDamage = baseDamage;
+    public void ModifyMoney(long amount, boolean dir) {
+        if (dir) {
+            Money += amount;
+        }
+        Money -= amount;
     }
 
-    void attack(Entity target);
+    public void RestoreHealth() { Health = MaxHealth; }
 
-    void defend();
-
-    void heal(int health);
-
-    void fillMana(int mana);
-
-    void takeDamage(int damage);
-
-    int getMaxHP();
-
-    int getMaxMP();
-
-    public void She() {
+    @Override
+    public void Heal(int amount) {
+        Health += amount;
 
+        if (Health > MaxHealth) {
+            Health = MaxHealth;
+        }
     }
 
-    /*
-    TODO: ADD OTHER REQUIRED AND BONUS METHODS
-    */
+    @Override
+    public IDefender[] GetDefenders() {
+        return new IDefender[]{Shield, Costume};
+    }
+
+    @Override
+    public void TakeDamage(int amount, AttackPowerUp[] powerUps) {
+        IDefender[] defenders = GetDefenders();
+
+        for (IDefender defender : defenders) {
+            if (defender != null) {
+                amount = defender.Apply(amount, powerUps);
+            }
+        }
+
+        Health -= amount;
+
+        if (IsDestroyed()) {
+            HandleZeroHealth();
+        }
+    }
+
+    @Override
+    public boolean IsDestroyed() {
+        return Health <= 0;
+    }
+
+    @Override
+    public void HandleZeroHealth() {
+        this.State = EntityState.DEAD;
+    }
+
+    public void SellItem(SellableItem item) {
+        int price = item.GetPrice();
+        RemoveFromInventory(item);
+
+        Money += price;
+    }
+
+    public void SellByClass(ItemClass itemClass) {
+        ArrayList<Item> items = GetInventoryByClass(itemClass);
+
+        for (Item item : items) {
+            SellItem((SellableItem) item);
+        }
+    }
+
+    public void AddToInventory(Item item) {
+        Inventory.add(item);
+    }
+
+    public void RemoveFromInventory(Item item) {
+        Inventory.remove(item);
+    }
 }