Tic-Tac-Toe
Find the winning move. Beat the AI in four in a row.
A new ranked puzzle drops every day. Each board is pre-loaded with pieces already in play — your job is to find the one move that forces a win. Make it in as few moves as possible and build your streak.
How to play
- You play as X. The AI plays as O.
- Get 4 in a row — horizontally, vertically, or diagonally — to win.
- Each puzzle starts with pieces already placed. One move creates a forced win.
- The AI plays perfectly after your move — find the right line before it counters.
- Fewer moves = a better record for that puzzle.
Your stats
Puzzle records — fewest moves to win
No records yet. Play a ranked puzzle to set one.
What is this game?
This is a tactical variant of Tic-Tac-Toe played on a 6×6 grid where four in a row wins. Unlike the classic 3×3 version, the larger board opens up genuine strategy: threats can come from multiple directions simultaneously, and the AI will exploit any gap you leave. Each puzzle loads a pre-arranged board and gives you a specific challenge — find the single move that creates an unstoppable fork.
A brief history
Tic-Tac-Toe in its 3×3 form is one of the oldest strategy games known, with roots in ancient Egypt. The name derives from a nineteenth-century British pencil-and-slate game played blind. The 4-in-a-row variant on larger grids is related to the Japanese game of Gomoku (five in a row on a 15×15 board), and to Connect Four — both of which were solved mathematically and shown to be first-player wins under optimal play. The 6×6 board with a win length of four sits between these extremes: small enough to hold in your head, large enough for real tactical depth.
Core strategy
The key concept in 4-in-a-row is the fork — a position where you create two simultaneous threats that cannot both be blocked. A single threat is easy to counter; two threats at once are not. Good opening play focuses on building a diagonal scaffold that can branch into either a horizontal or vertical completion, forcing the opponent to choose which threat to block while the other one lands. When you look at the pre-placed pieces on each puzzle, trace every partial line of three that belongs to X and ask: which extension creates a second line at the same time?
The AI in this game plays a strong defensive and offensive strategy. It will block any winning threat it detects, and it will build its own threats if you leave openings. This means you cannot simply extend the obvious line — you need to find a move that wins despite the AI's best response. In puzzle mode this is guaranteed to exist: every board has exactly one first move that forces the outcome regardless of what the AI does.
Ranked vs. free play
Each calendar day a new ranked puzzle is selected from the puzzle set — the same board for every player who visits that day. Completing the ranked game updates your streak and records the fewest moves you used to win. After the ranked game, you can explore any puzzle from the full set in free play. Free games do not count toward streaks or records, making them ideal for studying the position or just enjoying a rematch without pressure.
Tips for beginners
Start by scanning for any line of three that already exists — both yours and the AI's. If the AI has three in a row and can complete it, you must extend to block unless your winning move is available on this very turn. Next, look for diagonals: the pre-placed X pieces in each puzzle are always arranged diagonally, so your winning move is almost always one that extends that diagonal in a way that simultaneously threatens a cross direction. When in doubt, try the move that puts you closest to the centre of your existing cluster — centre mass gives the most branching options.