Acey-deucey is a variant of backgammon. Since World War I, it has been a favorite game of the United States Navy, Marine Corps, and Merchant Marine. Some evidence shows that it was played in the early 1900s aboard U.S. Navy ships. The game is believed to be rooted in the Middle East, Greece, or Turkey, where there were variants in which the game started with pieces off the board.
Compared to standard backgammon, acey-deucey is more like a race than a strategy game. It features a differing starting position, opening play, and rules for the endgame. Because pieces may be retained in one's opponent's home board, the game offers substantial opportunities for backgame play.
The components of acey-deucey match those of backgammon, including identical boards, number of pieces, and dice. Unlike standard backgammon, all of both players' pieces are off the board when the game begins. Acey-deucey does not use the doubling cube.
The initial play is markedly different from that of standard backgammon. Pieces are entered onto the opponent's inner board as if they were on the bar. Once a piece has been entered, it can be moved even though other pieces haven't been entered. One strategy in the game is to keep one man, called an "Oscar", off the board until it is needed for defensive purposes.
Play passes back and forth, with each player rolling both dice.
A player who rolls doubles may move a total of four times, each move traversing as many spaces as the rolled amount (two fives rolled result in four moves of five points each). After rolling these doubles, the player takes another turn.
If a player rolls an acey-deucey (= a 1 and a 2), he plays the 1-and-2; then he chooses any number from 1 to 6 and acts as if had just thrown a double of it; then he takes another turn.
After the opening, gameplay is nearly identical to that of backgammon, with some notable differences:
The terminology of acey-deucey is somewhat different from that of backgammon. The initial rolling of one die is called the peewee or piddle. The bar is the fence, and a single man is kicked rather than hit. The opponent's inner table is called the entering table or starting quarter, and one's own inner table is the finishing quarter.
Variants of the above rules exist that make the game more restrictive.