Gomoku

Put your piece on any unoccupied spot of the board. Strive to create a line of 5 pieces in a line, either sideways, vertically, or diagonally. Block your rival from completing their own sequence of five. Switch placing stones with your opponent until one contestant succeeds in forming a line of five. Note that the match ends immediately when a line of 5 is created, with no need to occupy the entire board.