diff --git a/src/game/Ball.ts b/src/game/Ball.ts
index 93e9a4e..e8651e1 100644
--- a/src/game/Ball.ts
+++ b/src/game/Ball.ts
@@ -4,7 +4,7 @@ import {choice} from "../utils";
 import {defaultBallSpeed, startAngles} from "./parameters";
 
 export class Ball {
-    private _position: Position;
+    public position: Position;
     private phi: number;
     private speed: number;
     private readonly element: HTMLElement;
@@ -20,13 +20,10 @@ export class Ball {
         this.redraw();
     }
 
-    set position(position: Position) {
-        this._position = position;
-    }
-
     public readonly redraw = (): void => {
-        this.element.style.left = this._position.x + "px";
-        this.element.style.top = this._position.y + "px";
+        console.log(this.phi / Math.PI, this.position.x, this.position.y);
+        this.element.style.left = this.position.x + "px";
+        this.element.style.top = this.position.y + "px";
     }
 
     public readonly setup = (gameElement: HTMLElement): void => {
@@ -39,7 +36,12 @@ export class Ball {
     }
 
     public readonly tick = (delta: number): void => {
-        this._position = this._position.moveInDirection(this.phi, this.speed * delta / 1000);
+        this.position = this.position.moveInDirection(this.phi, this.speed * delta / 1000);
         this.redraw();
     }
+
+    public readonly collision = (wallAngle: number): void => {
+        this.phi = 2 * wallAngle - this.phi;
+        this.phi -= (0|(this.phi / (Math.PI*2))) * Math.PI * 2;
+    }
 }
\ No newline at end of file
diff --git a/src/game/Game.ts b/src/game/Game.ts
index 004a031..986354c 100644
--- a/src/game/Game.ts
+++ b/src/game/Game.ts
@@ -46,9 +46,29 @@ export class Game {
         const delta = timestamp - this.lastTickTimestamp;
         this.lastTickTimestamp = timestamp;
 
-        this.balls.forEach(ball => ball.tick(delta));
+        this.balls.forEach(ball => {
+            ball.tick(delta);
+            this.handleCollisions(ball);
+        });
+
         if (this.running) {
             requestAnimationFrame(this.tick);
         }
     }
+
+    private readonly handleCollisions = (ball: Ball): void => {
+        this.handleEdgeCollisions(ball);
+    }
+
+    private readonly handleEdgeCollisions = (ball: Ball): void => {
+        if (ball.position.x < 0) {
+            ball.collision(Math.PI / 2);
+        } else if (ball.position.x >= fieldWidth) {
+            ball.collision(Math.PI / 2);
+        } else if (ball.position.y < 0) {
+            ball.collision(0);
+        } else if (ball.position.y >= fieldHeight) {
+            ball.collision(0);
+        }
+    }
 }