Classic Games
Bidding Tic-Tac-Toe
Tic-tac-toe with NO turns: every move goes to the higher SEALED BID — and the winner pays their chips to the opponent. Suddenly the kids' game is a masterclass in valuation: most moves are worth almost nothing, one move is worth everything, and finding which is which is the whole sport. Hiding underneath: a real theorem connecting bidding games to coin-flip games. Solo bot ladder + live class arena.
For Educators
Built for the classroom
Resource valuation and threat assessment — Richman games made playable. Students discover that a move's fair price is how much it CHANGES the game (most are near-worthless; a fork is worth everything), that overpaying loses wars while underpaying loses moments, and the stunner: the bidding game and the COIN-FLIP version of the same game are mathematically the same (the Dojo's Mirror lab lets them measure it — coin-flip win rates land exactly on the boss bot's chip prices). The boss, The Banker, prices every move from an exact 19,683-position analysis; beating him takes positional play, not just money.
Grades 5+ · treasuries: Classic 100 chips, Quick 30 (chunky decisions), or Coin-flip mode (the secret twin) · ⭐ tie-break token (ties go to the holder, then it swaps).
Three ways to play
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Learn solo first
Four bots, all open from the start: Penny, Buck, Goldie, The Banker. Each spends by a different idea — placement skill and bid skill fail separately, and the ladder teaches both.
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Host an Arena
Open a room on the projector; pick the treasury; best-of-2 with the ⭐ starting on opposite sides. A full board goes to whoever kept more chips — frugality counts.
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Join on any device
Students seal bids in secret (the room only sees a 🔒 flag), then the auction reveals who paid what. Matches rotate so everyone plays everyone.
Run a live class in 5 steps
- Open the Arena — pick Classic 100 or Quick 30 chips and the move timer.
- Share the 4-letter code / QR / link; students join on any device.
- Each ply: both seal a bid → the reveal shows both amounts and who paid whom → the buyer places.
- Ask the room mid-game: what just sold for 5 chips? What sold for 60? What was DIFFERENT about the board?
- Run the Coin-flip mode once afterwards and ask why the no-chips game feels familiar. Don't answer — the Dojo will.
Tip: host on a laptop or projector (the big screen shows the code, QR and leaderboard); students join on their phones or laptops.
