Recursive strategy · Depth 1–4
Think deeper
than your rival.
Super Tic-Tac-Toe where every square is its own board. Pick a recursion depth — from nine squares to six thousand five hundred and sixty-one — and outmaneuver a friend on one device or across the world.
Online rooms · no account needed · free at every depth
Choose your depth
Four levels of recursion
Same rules at every depth. Only the scale of your thinking changes. Every depth is free, forever.
Ultimate selected · 81 squares · pick how you play
Play online
Open a room and share a six-character code or a link. Two phones, two laptops, two continents. No account needed on either side.
Have a room code? Join a friend's tablePass & play
One device, two players taking turns. The fastest way to learn the rules at this depth.
Every square is a board
At depth two, the nine squares of the main board each hold another board. Deeper depths nest again — down to 6,561 playable squares.
Your move routes your rival
Where you play decides where they must play next. Win a small board and its square belongs to you — three claimed squares take the board above it.
Victories climb the tree
A won board counts as one mark in its parent. Keep propagating upward until you claim the root board. Decided boards relax the routing so nobody is ever trapped.
Optional support
The Founder's Pack
One purchase, no subscription. Exclusive board themes, animated marks, and a founder badge beside your name. Nothing here changes a single rule — the game stays free, and nothing paid ever buys an advantage.
$4.99once
View the pack