# bounciness

> Coefficient of restitution.

## Definition

* **Type:** Property
* **Namespace:** [UnityEngine](/engine/6000.3/script-reference/unityengine.md)
* **Assembly:** UnityEngine.Physics2DModule

```csharp
public float bounciness { get; set; }
```

### Remarks

Restitution (bounciness) is used to control how "elastic" a collision response is. A value of zero indicates no bounce at all while a value of one indicates perfect elasticity (approximately).

**Note:** Values higher than one are allowed but will add "energy" to the collision response. Use caution, as this can cause a [Rigidbody2D](/engine/6000.3/script-reference/unityengine/rigidbody2d.md) to move quickly without limit, leading to simulation problems.