diff --git a/.gitignore b/.gitignore
index 70660bf..716567b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -53,6 +53,7 @@ dist/
 nbdist/
 nbactions.xml
 nb-configuration.xml
+.nb-gradle/
 
 ## Gradle
 
diff --git a/core/src/com/saltosion/gladiator/components/CPhysics.java b/core/src/com/saltosion/gladiator/components/CPhysics.java
index f3d3824..97b7ef9 100644
--- a/core/src/com/saltosion/gladiator/components/CPhysics.java
+++ b/core/src/com/saltosion/gladiator/components/CPhysics.java
@@ -2,6 +2,7 @@ package com.saltosion.gladiator.components;
 
 import com.badlogic.ashley.core.Component;
 import com.badlogic.gdx.math.Vector2;
+import com.saltosion.gladiator.physics.CollisionListener;
 
 public class CPhysics extends Component {
 
@@ -10,6 +11,7 @@ public class CPhysics extends Component {
     public Vector2 size = new Vector2();
     public float movespeed = 5f, jumpForce = 0.3f, gravity = 1f;
     public boolean grounded = true;
+    public CollisionListener collisionListener = null;
 
     // Movable toggles if the entity can move by itself
     public boolean movable = true;
@@ -48,4 +50,9 @@ public class CPhysics extends Component {
         return this;
     }
 
+    public CPhysics setCollisionListener(CollisionListener collisionListener) {
+        this.collisionListener = collisionListener;
+        return this;
+    }
+
 }
diff --git a/core/src/com/saltosion/gladiator/physics/CollisionListener.java b/core/src/com/saltosion/gladiator/physics/CollisionListener.java
new file mode 100644
index 0000000..286d35e
--- /dev/null
+++ b/core/src/com/saltosion/gladiator/physics/CollisionListener.java
@@ -0,0 +1,22 @@
+package com.saltosion.gladiator.physics;
+
+import com.badlogic.ashley.core.Entity;
+
+/**
+ *
+ * @author Jens "Jeasonfire" Pitkänen <jeasonfire@gmail.com>
+ */
+public interface CollisionListener {
+
+    /**
+     * This method will be called when host collides with other
+     *
+     * @param side The side which host is colliding other with. Eg. if host is
+     * falling towards other, this argument will be CollisionSide.BOTTOM when
+     * the collision happens.
+     * @param host
+     * @param other
+     */
+    public void collision(CollisionSide side, Entity host, Entity other);
+
+}
diff --git a/core/src/com/saltosion/gladiator/physics/CollisionSide.java b/core/src/com/saltosion/gladiator/physics/CollisionSide.java
new file mode 100644
index 0000000..a479307
--- /dev/null
+++ b/core/src/com/saltosion/gladiator/physics/CollisionSide.java
@@ -0,0 +1,11 @@
+package com.saltosion.gladiator.physics;
+
+/**
+ *
+ * @author Jens "Jeasonfire" Pitkänen <jeasonfire@gmail.com>
+ */
+public enum CollisionSide {
+
+    TOP, BOTTOM, LEFT, RIGHT
+
+}
diff --git a/core/src/com/saltosion/gladiator/systems/PhysicsSystem.java b/core/src/com/saltosion/gladiator/systems/PhysicsSystem.java
index 13e6139..1659c93 100644
--- a/core/src/com/saltosion/gladiator/systems/PhysicsSystem.java
+++ b/core/src/com/saltosion/gladiator/systems/PhysicsSystem.java
@@ -7,6 +7,7 @@ import com.badlogic.ashley.core.EntitySystem;
 import com.badlogic.ashley.core.Family;
 import com.badlogic.ashley.utils.ImmutableArray;
 import com.saltosion.gladiator.components.CPhysics;
+import com.saltosion.gladiator.physics.CollisionSide;
 
 /**
  *
@@ -54,8 +55,7 @@ public class PhysicsSystem extends EntitySystem {
                     if (i == j) {
                         continue;
                     }
-                    CPhysics other = pm.get(entities.get(j));
-                    collision(obj, other);
+                    collision(entities.get(i), entities.get(j));
                 }
             }
 
@@ -64,7 +64,10 @@ public class PhysicsSystem extends EntitySystem {
         }
     }
 
-    public void collision(CPhysics cp0, CPhysics cp1) {
+    public void collision(Entity entity0, Entity entity1) {
+        CPhysics cp0 = pm.get(entity0);
+        CPhysics cp1 = pm.get(entity1);
+
         float x00 = cp0.position.x - cp0.size.x / 2;
         float x01 = cp0.position.x + cp0.size.x / 2;
         float x10 = cp1.position.x - cp1.size.x / 2;
@@ -86,6 +89,10 @@ public class PhysicsSystem extends EntitySystem {
                 // cp0 is going left, stop
                 cp0.velocity.x = 0;
             }
+
+            if (cp0.collisionListener != null) {
+                cp0.collisionListener.collision(CollisionSide.LEFT, entity0, entity1);
+            }
         }
         if (x01 > x10 && Math.abs(x01 - x10) < (cp0.size.x + cp1.size.x) / 16) {
             // cp0's right side is colliding with cp1's left side
@@ -93,6 +100,10 @@ public class PhysicsSystem extends EntitySystem {
                 // cp0 is going right, stop
                 cp0.velocity.x = 0;
             }
+
+            if (cp0.collisionListener != null) {
+                cp0.collisionListener.collision(CollisionSide.RIGHT, entity0, entity1);
+            }
         }
         if (y00 <= y11 && Math.abs(y00 - y11) < (cp0.size.y + cp1.size.y) / 16) {
             // cp0's bottom side is colliding with cp1's top side
@@ -101,7 +112,10 @@ public class PhysicsSystem extends EntitySystem {
                 cp0.velocity.y = 0;
             }
             cp0.grounded = true;
-            //cp0.position.y -= Math.abs(y00 - y11);
+
+            if (cp0.collisionListener != null) {
+                cp0.collisionListener.collision(CollisionSide.BOTTOM, entity0, entity1);
+            }
         }
         if (y01 > y10 && Math.abs(y01 - y10) < (cp0.size.y + cp1.size.y) / 16) {
             // cp0's top side is colliding with cp1's bottom side
@@ -109,6 +123,10 @@ public class PhysicsSystem extends EntitySystem {
                 // cp0 is going up, stop
                 cp0.velocity.y = 0;
             }
+
+            if (cp0.collisionListener != null) {
+                cp0.collisionListener.collision(CollisionSide.TOP, entity0, entity1);
+            }
         }
     }