Ball Bounce with Random Range

Following a tutorial, I have created a ball that bounces along 3 walls with a paddle at the bottom, like the game Pong. Sometimes the ball gets stuck in a straight line bounce loop, bouncing from one wall to the other and back with no variation. I’d like to add a bit of randomness to the bounce angle to the ball so that it doesn’t get stuck.

I found a similar question answered already, but it was answered with C#, and the tutorial script is in javascript. Everything I tried did not work. Would Random range and vector help? I don’t know how to implement them into the script.

Part of the script added to the ball:

function Awake(){
 rigidbody.AddForce(8, 4, 0, ForceMode.Impulse);
 InvokeRepeating("IncreaseBallVelocity", 2, 2);
}

function IncreaseBallVelocity(){
 rigidbody.velocity *= 1.05;
}

I guess you could just add some force when it hits:

 function OnCollisionEnter(other : Collision) {
      rigidbody.AddForce(Random.insideUnitCircle * 10, ForceMode.Impulse); // or some other multiplier
 }