XO Ultimate: Notebook Edition

Think you've mastered Tic-Tac-Toe? Try it on a bigger board against an AI that actually plans ahead. XO Ultimate is a strategy puzzle game built on the classic pen-and-paper grid. Play 3x3, 4x4, or 5x5 boards, face up to three AI opponents, or pass the phone around with friends. The game works offline, so you can play anywhere. BIGGER BOARDS, REAL STRATEGY 3x3 keeps the classic rules: first to line up three wins. On 4x4 and 5x5 boards, the game runs until the grid is full and points decide the winner: - 3 in a row: 1 point - 4 in a row: 3 points - 5 in a row: 6 points - Every move is a trade-off between building a long line and blocking your opponent. AN AI THAT THINKS The AI uses Negamax search with alpha-beta pruning, iterative deepening, and a custom evaluation, across four levels: Easy, Medium, Tough, and Impossible. Want chaos? Play against up to three bots at once, each set to a higher difficulty. PASS & PLAY FOR 2 TO 4 PLAYERS Local multiplayer on one device. No account, no setup. POST-MATCH ANALYSIS Review your game move by move. Each move is rated Blunder, Mistake, Inaccuracy, Good, or Best. Use Try Best Move to branch off from a mistake and see how the game could have gone. In Pass & Play, an Intelligence Rating report compares how the players performed. Analysis and Intelligence reports are unlocked by watching an optional rewarded ad. BRAIN SCORE Every match against the AI updates your Brain Score, an ELO-style rating that rises and falls with your results. Climb through six tiers: Beginner, Amateur, Intermediate, Advanced, Master, and Grandmaster. STREAKS AND UNDOS Play one match a day to keep your streak going. Each Vs AI game includes one Undo, and you can earn more through rewarded ads. Reach a 7 day streak and every ad gives you 2 bonus Undos. HAND-DRAWN LOOK AND FEEL A notebook and pen design with light and dark themes, sound effects, and haptic feedback. Theme, sound, haptics, and privacy options all live in one settings menu. PRIVACY Your game progress, stats, and settings stay on your device, and XO Ultimate does not collect your data for itself. Ads are served by Google AdMob, which may collect data for advertising. You choose your ad preferences in Google's consent form on first launch (GDPR and CCPA compliant, in EEA/UK and similar regions). GOOD FOR Puzzle fans, board game lovers, casual players who want a quick match, and anyone who finds regular Tic-Tac-Toe too easy. Download XO Ultimate and see how high your Brain Score can climb.