Rev4 The game Reversi on a 4 by 4 Board. The board is a 4x4 grid.

The object of the game is to have more pieces of the player's color than the opponent's the board at the end of the game. The game is over when neither player has a move.

Usually, this means when the board is full. A game has at most 16 moves. When playing with physical game pieces, each piece has a black side and a white side. Each player is one of the colors. Black goes first and play alternates between the colors. Each player places one piece on the board in a turn.

First Four Moves: The board begins empty. The first 4 moves of the game must be in the four central cells of the board. So, at the end of move 4, the pieces will form either a parallel or crossed pattern

Further Moves: After the first 4 moves of the game, any move must bookend (flank or surround or "sandwich" in a straight line) one or more pieces of the opposing color which are then "flipped" to become the color of the moving player. The flip can occur in vertical, horizontal, and diagonal rows of pieces. More than one direction can be flipped by a single move. For example: From , Black moves in the leftmost cell, which flips the White piece: . From , Black's move in the corner flips White pieces in two directions: .

Cannot Move: If a player cannot move, that player's turn is skipped (the opponent plays again). Example where Black cannot move:

End of the Game: Play ends when no one can move, most often when the board is full. At the end of play, the color with the most pieces wins. A tie (draw) can occur.