Super Tic Tac Toe

The game of super tic-tac-toe (or ultimate tic-tac-toe, or whatever else you might want to call it) created using Svelte and PeerJS. Playable on a single device or across the internet.

Icons from Material Symbols.

Rules (Wikipedia)

Each small 3 × 3 tic-tac-toe board is referred to as a local board, and the larger 3 × 3 board is referred to as the global board.

The game starts with X playing wherever they want in any of the 81 empty spots. This move "sends" their opponent to its relative location. For example, if X played in the top right square of their local board, then O needs to play next in the local board at the top right of the global board. O can then play in any one of the nine available spots in that local board, each move sending X to a different local board.

If a move is played so that it is to win a local board by the rules of normal tic-tac-toe, then the entire local board is marked as a victory for the player in the global board. Once a local board is won by a player or it is filled completely, no more moves may be played in that board. If a player is sent to such a board, then that player may play in any other board. Game play ends when either a player wins the global board or there are no legal moves remaining, in which case the game is a draw.