Tak

1. The goal. Connect two opposite edges of the board — left to right, or bottom to top — with an unbroken orthogonal chain of squares you control. That chain is a road, and building one wins immediately. Diagonals do not connect.

2. Your turn is one thing. Either place one piece from your reserve on an empty square, or move a stack you already control. Never both.

3. Three kinds of piece.

• ▪ A flat stone lies down. It counts for roads and it counts for the flat score. This is almost every piece you play.
• ▮ A standing stone (a wall) is the same stone stood on its edge. It does not count for roads or score, but nothing can be stacked on top of it. Walls are how you cut a road.
• ⬤ The capstone counts for roads, cannot be covered by anything, and is the only piece that can knock a wall flat — and only when it moves onto that wall alone. You get one on a 5×5 or 6×6, two on 7×7 and 8×8, none below that.

4. The odd first move. On your very first turn you place one of your opponent's flat stones, anywhere. Both players do this, so the game opens with each of you having given the other a stone. It stops the first player running away with the tempo.

5. Moving a stack. You control a stack if your piece is on top — whatever is buried under it, of either colour, comes along for the ride. Lift up to as many pieces as the board is wide (five on a 5×5), move in one straight orthogonal direction, and drop at least one piece on every square you pass over. You cannot turn a corner, jump a square, or skip a drop. The pieces at the bottom of what you lifted come off first.

6. What blocks you. Flats can always be covered. Walls block everything except a lone capstone. Capstones block everything, full stop.

7. The other way to win. If the board fills up, or either player places their very last piece, the game ends there and you count flats on top — walls and capstones do not count. Most flats wins; equal is a draw. This is why burying an opponent's flat is worth something even when it builds no road of your own.

If you take one idea away: a wall is a stone you have taken out of the scoring to buy a blockade, and a capstone is the tool for undoing somebody else's. Everything interesting in Tak is a fight over whose stone is on top.

Sizes and reserves. 3×3: 10 stones, no capstone. 4×4: 15, none. 5×5: 21 + 1 capstone. 6×6: 30 + 1. 7×7: 40 + 2. 8×8: 50 + 2. Carry limit always equals the board size.

Both roads at once. If a single move completes a road for both players, the player who made the move wins.

Flattening. A capstone flattens a wall only when it is the sole piece dropped on that square. Carrying anything underneath it means the wall still blocks.

Notation. This board writes moves in PTN. c3 places a flat, Sc3 a wall, Cc3 the capstone. 3c3>111 lifts three pieces from c3, moves right, and drops one on each of d3, e3, f3. < is left, > right, + up, - down; a trailing * means a wall was flattened.

Ending. Road wins are immediate. Otherwise the game ends when the board is full or a player's reserve empties, and the higher flat count wins.

Tak was designed by James Ernest and Patrick Rothfuss, from the game described in Rothfuss's The Wise Man's Fear. The rules are freely available and this is a non-commercial implementation of them; no artwork or text from the published game is used.