Page "Backgammon" Paragraph 11

In the course of a move, a checker may land on any point that is unoccupied or is occupied only by a player's own checkers.

It may also land on a point occupied by exactly one opposing checker, or " blot ".

In this case, the blot has been hit, and is placed in the middle of the board on the bar that divides the two sides of the playing surface.

A checker may never land on a point occupied by two or more opposing checkers ; thus, no point is ever occupied by checkers from both players simultaneously.