9 boards in one · your move picks their board
Ultimate Tic-Tac-Toe
Nine tic-tac-toe boards nested in one grid: the cell you pick decides which board your opponent must play next. Three big cells in a row wins.
Boards glowing blue are where you're allowed to play. If you're sent to a finished board, you may play anywhere. Sending your opponent to a board they've already lost control of is the key tactic.