Application of UCT Search to the Connection Games of Hex, Y, *Star, and Renkula!

Play-out analysis has proved a succesful approach for artifi cial intelligence (AI) in many board games. The idea is to play numerous times from the current state to th e end, with randomness in each play-out; a good next move is then chosen by analyzing the set of play-ou ts and their outcomes. In this paper we apply play-out analysis to so-called ‘connection games’ , abstract board games where connectivity of pieces is important. In this class of games, evaluating th e game state is difficult and standard alphabeta search based AI does not work well. Instead, we use UCT se arch, a play-out analysis method where the first moves in the lookahead tree are seen as multi-a rmed bandit problems and the rest of the play-out is played randomly using heuristics. We demons trate the effectiveness of UCT in four different connection games, including a novel game called R nkula!.