TwixT is a connection game invented by Alex Randolph. It is played on board with a 24×24 grid of holes, with the four corners missing. The two players are White and Red; the topmost and bottommost rows belong to White, and the leftmost and rightmost rows belong to Red. (Different sets may use different colors.)
The rules are as follows:
- The players take turns placing pegs of their respective colors on the board, one peg per turn.
- A player may not place a peg on the rows which belong to his or her opponent.
- White places the first peg. To counteract first-move advantage, the swap rule is suggested. (This "one-move equalization" was added by Randolph after 3M published his game. It is present in the Schmidt Spiele edition and all later editions.)
- After placing a peg, you may link one or more pairs of pegs on the board which are all your own color. The links can only go between two pegs a knight's move away from each other, and cannot cross another link; they block other links, most importantly the opponent's. You may remove your own links (but not your opponent's) in order to rearrange the sequence of links on the board. (There is a pencil and paper variant, often called TwixtPP: you may cross your own links but not your opponent's. Crossed links are not inherently connected to each other. In other words, the object is still to form a sequence of your pegs, each linked to the next, which connects your border rows. The course of a match usually does not depend on which variant is used.)
- The first player to make a continuous chain of linked pieces connecting their two sides wins. If neither side can achieve this, the game is a draw.