Five in a Row

Take Four in a Row and remove gravity. A stone goes wherever you put it, so a board that offered you seven moves now offers two hundred and twenty-five. That is the whole difference between a game that has been solved and one people still play in tournaments.

The board is fifteen squares each way. First to line up five wins, in any direction, and a longer line counts as well. Tournament play uses opening rules to blunt the advantage of moving first. This version does not. It alternates who opens instead, which is the same fix without a rule you have to memorise. If you learned it as gomoku or omok, the goal is the one you know, and nothing is banned.

Three strengths of opponent. Easy takes a win it can see and blocks a loss it can see, and misses whatever is being set up behind them. Medium looks two moves ahead. Hard looks four, and it will punish an open three you leave unguarded. A square here is about twenty pixels across on a phone, so the first tap aims and the second places. Tap elsewhere and the aim moves with you. A slip costs you nothing.