Pente

Five-in-a-row with a bite — the 1977 classic, you (black) versus a threat-and-capture CPU (white). Place stones on a 13×13 grid and line up five in a row to win. But there's a twist that sets Pente apart from plain Gomoku: bracket exactly two of the opponent's stones between two of yours and you capture the pair, lifting them off the board — and capturing five pairs is itself a win. Captures snap lines apart and open fresh threats, so every stone is both a spearhead and a target. Critically, you may safely move into a flank — only the player who brackets a pair captures it.