Backspin or a slice is a shot that is the complete opposite of topspin. This makes it harder for the opponent to get the ball, as it travels in an unnatural direction. When a shot with backspin is hit, the ball curves to the side. When this type of shot is hit in table tennis, the ball should be allowed to hit the table unlike tennis, where you can volley the ball. Backspin slows the ball down and does not lower the elevation as drastically as topspin. The only other sport this is commonly used in, is golf.