Chopsticks (hand game)

The game's scores are tracked on the fingers of both hands

Chopsticks is a hand game for two players, in which players extend a number of fingers from each hand and transfer those scores by taking turns to tap one hand against another.^[1] The basic version is an example of a solved game in that so long as both players play optimally, the game's victor can be predicted at any point.^[2]

Rules

Each player uses both hands to play the game, the number of digits extended on a hand showing the number of points that the hand has. Both players start with each hand having one point — one finger extended on each hand. The goal of the game is for a player to force their opponent to extend all of their fingers and thumbs on both hands. A hand with all fingers and its thumb extended is called a "dead hand". Players take turns to tap one of their hands against another hand that is not dead (either their own other hand, or one of their opponent's). The number of points on the tapping hand is added to the number on the tapped hand, and the player with the tapped hand extends their digits to show the new score. The tapping hand remains unchanged.

A player may tap their own hand to transfer points from one hand to the other. For example, if a player had three points on his or her right hand and one on his or her left, the player could rearrange them to have two on each hand. A player may not transfer points to their own hand and make it a dead hand. A player cannot prolong the game by not taking their turn. ^[3]

Splitting

Splitting can be used to "revive" a dead hand. In such cases, a "dead" hand is treated as having a score of 0. For example, if a player have 5/2 (one dead hand and other hand having 2 points), they can split 1/1 (one hand has 1 point the other has 1 point). If the player have 5/3, they can split 2/1 or 1/2. If the player have 5/4, they can split 2/2, 3/1, or 1/3. This move can only legally be performed if it results in a legal score and the resulting hand is different from the initial hand; i.e., switching 2/2 to 4/0 or 2/2 is illegal, while switching to 3/1 or 1/3 are legal plays.

In some variations of chopsticks, it is allowed to use this move to stall the game: if one has 2/3, one can split the chopsticks to make a score of 3/2, essentially "switching" the two hands and passing a turn.

Also, in other variations, while having 5/1 (one dead hand and one with one finger), it is a legal move to switch to 1/5, which is another was of "passing" on your move.

In other variants, players can only split 4 fingers or 2 fingers, and must split to an equal number of fingers on each side.

See also

• Morra (game) - a different hand-game, which is based on chance rather than logic.

References

1. "Chopsticks Game". Activity Village. Retrieved 2014-03-27.
2. Rigney, Ryan (2012-11-07). "You May Win Every Time, But You Haven't Solved This Game Yet". Wired. Retrieved 2014-03-27.
3. "Chopsticks". Childhood, Tradition & Change. 2011. Retrieved 2014-03-27.

External links

• Unbeatable Chopsticks AI Bot. This bot plays the game with remainders and transfers.