first peg is placed, then sides may not be swapped later in that game. (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, a player may link one or more pairs of pegs on the board of their colour. The links can only connect two pegs a knight's move away from each other, and cannot cross another link; they block other links, most importantly those of the opponent. As part of the player's move, they may remove their own links (but not those of the opponent) in order to rearrange the sequence of links on the board. A variant for pencil and paper play allows a connection to cross the player's links but not those of the opponent. The object is to make a continuous chain of linked pegs connecting the player's border rows. If neither player can achieve this, the game is a draw. Computational complexity for general rectangular boards TwixT has been proven to be PSPACE-complete for determining the game value, via a reduction from Hex. TwixT has also been shown to be NP-complete regarding whether a single set of vertices can support a connecting path, via a reduction from 3-satisfiability. These proofs are indicative of a complex strategy: the game has not been solved, no winning strategy has been discovered, nor is the outcome of the game with perfect play known. Related games On the 24×24 grid, tactical considerations tend to predominate. The opening phase is over quickly, and the rest of the game is spent attempting to tactically execute the plan. Hex, which has a very similar game object, may have more predictable tactics, but strategical considerations are much more important. In this sense, Hex is more like Go than TwixT, since a single move is generally less committal, and consequences may take longer to play out. Variants One variant is Twixt PP (Paper and Pencil). The rules are almost identical to standard TwixT, except links are never removed and a player's own links are allowed to cross each other. A winning path might loop across itself but crossed links are not connected to each other at the intersection. The paper and pencil rules may reduce the number of draws (which are already rare). Whether it reduces the complexity of the game or not is highly debatable.