Go is a very simple game to describe but incredibly difficult to play well. Two players take it in turns to place single stones on the board. The object of the game is to surround the most territory. Black always plays first.
You may capture an opponent's stone or stones by surrounding them. Here are two examples where placing a white stone in the pink area will capture the enclosed black stones
Atari Go is a simplified version which enables beginners to become familiar with the real game. In this version the goal is to simply make the first capture.