WU (1982)

WU claims Go ("WEI-CHI'I") as its ancestor; contemporary gamers will note it is very similar to Pente, with several key differences. The game is played with small colored glass stones on a 19x19 vinyl mat that rolls up into a tube-like box, and is organized into three difficulty levels: Basic, Intermediate, and Advanced. Like its ancestor and contemporaries, WU is played by taking turns placing the stones on grid points. At the Basic level, the winning condition is simply to place five pieces in a row vertically, horizontally, or diagonally. The Intermediate Level adds the winning condition of seizing five pairs of the opponent's stones. Unlike Pente, these stones are left on the board, not removed. Players are required to notify their opponent of the danger of seizure, by saying "Chiau Tsi" or "stones seized." Advanced difficulty adds the use of sand timers to force players to think quickly when making their every move. Though two sets of stones are included, the instructions allow that up to four can play with additional colors of stones.