When a ball is unplayable in a bunker you still have all three of the same relief options as are available in the general area for one penalty stroke:

1. Stroke-and-distance relief
2. Back-on-the-line relief
3. Lateral relief

BUT – if you chose back-on-the-line or lateral relief, the relief area must be inside the same bunker.

As an additional option to get out of the bunker, you can use back-on-the-line relief and drop behind the bunker. But to use this option you get two penalty strokes.