Game objective and winning condition
Quoridor is a two-player game on a 9×9 board. You win by being the first player to move your pawn onto any one of the 9 squares of the opposite edge, the edge your opponent started on. You don't need to land on a particular square, and you win the moment you arrive.
Nothing is captured and nothing is removed from the board. The game is a race in which walls make a route longer, so each player's goal edge is simply the other player's starting edge.
This page describes the two-player game. The official four-player version uses the same rules with 5 walls per player and a pawn on each edge. It is not covered here and is not available on this site.
Board layout, player positions and pieces
A standard set has one board with 81 squares, 20 walls and 4 pawns. A two-player game uses two pawns and all 20 walls.
- Board. 9 rows by 9 columns of squares, separated by thin grooves.
- Pawns. One per player. Each player starts on the middle square (the fifth of nine) of their own edge, so the two pawns face each other across the board.
- Walls. A wall is two squares long. It is placed in the grooves between squares, never on a square.
Standard setup and walls per player
In a two-player game each player takes 10 walls and keeps them to the side. Both pawns go on the middle square of their starting edge.
| Item | Two-player game |
|---|---|
| Board | 9×9 squares (81) |
| Pawns | 1 per player, on the middle square of its own edge |
| Walls | 10 per player (20 in the set) |
| Wall length | 2 squares |
| Wall positions | 8 × 8 in each of 2 orientations (128 in total) |
The official rulebook has the players draw lots to decide who starts. On this site, Player 1 (the filled cyan pawn that starts at the bottom) always moves first in same-device and computer games. In online games the server picks who goes first at random, and a rematch swaps the order.
Turn order: move the pawn or place a wall
Players alternate turns. On your turn you do exactly one of these two things:
- move your pawn, or
- place one of your walls.
You can't do both and you can't pass. Once you have placed all 10 of your walls, you can only move your pawn.
Legal pawn movement
- A pawn moves one square up, down, left or right. Moving backwards or sideways is allowed.
- A pawn can't move diagonally, apart from the sidestep described in the next section.
- A pawn can't pass through a wall. It has to go around. A wall blocks movement across its groove in both directions.
- A pawn can't leave the board and can't end its move on the other pawn's square.
Jumping over an opponent and special movement situations
When the two pawns stand on neighboring squares that are not separated by a wall, the player whose turn it is may jump over the opponent's pawn and land on the square directly behind it, advancing an extra square. The jump is your whole move for that turn. It is a choice, never an obligation.
When the jump is blocked: the sidestep
If a wall is directly behind the pawn you would jump, you can't jump. Instead you may place your pawn on a square to the left or to the right of the opponent's pawn. This is the one situation in which a pawn moves diagonally.
Details that matter
- A wall between the pawns blocks the jump. Neighboring pawns separated by a wall can't jump over each other. Each is simply blocked in that direction.
- The sidestep squares must be reachable. You can't step to a side square if a wall lies between it and the opponent's pawn.
- Jumps work in every direction. Forwards, backwards or sideways, whenever the two pawns are neighbors.
- The board edge. The official rulebook mentions only a wall behind the jumped pawn. This site treats the board edge the same way: with no square to land on, you sidestep instead.
Wall placement, orientation and restrictions
A wall covers the length of two squares and sits exactly in the grooves between two sets of two squares. It is either horizontal (blocking movement up and down) or vertical (blocking movement left and right).
A wall placement is legal only if all of these are true:
- You have a wall left. Each player has 10.
- It lies fully on the board, centered between two pairs of squares. There are 8 × 8 positions in each orientation.
- It does not overlap another wall, not even by one square.
- It does not cross another wall. A horizontal and a vertical wall can't share the same middle point.
- It leaves every player a route to their goal edge (see the next section).
Walls may touch end to end or meet at a right angle, and you can place them in front of your opponent or anywhere else. Once placed, a wall stays for the rest of the game. It can't be moved, rotated or taken back.
The legal route rule
You may place a wall to slow your opponent or to protect your own path, but you may never leave any player, yourself included, with no route at all to their goal edge. The official rulebook puts it as: an access to the goal line must always be left open.
- Check both pawns before you place a wall. Each must still have a path of legal one-square steps to at least one square of its goal edge.
- A wall that makes a route much longer is perfectly legal. Only a wall that makes it impossible is forbidden.
- For this check, only walls count as obstacles. Pawns are ignored because they move and can be jumped. This is how this site enforces the rule.
- The check applies to the position after your wall is placed, with all earlier walls in place. A wall that is legal now can become illegal later, once other walls have been added.
Common illegal moves, with examples
These are the attempts that break the rules most often. The game on this site refuses each of them and says why.
| Illegal move | Why it's illegal |
|---|---|
| Moving two squares in one turn | A pawn moves one square. The only extra distance comes from a jump, which lands behind the opponent's pawn. |
| Moving diagonally on an open board | A diagonal step exists only as the sidestep when a straight jump is blocked. |
| Walking through a wall | A wall blocks movement across the groove it sits in. |
| Jumping over a pawn through a wall | A jump needs neighboring pawns that are not separated by a wall. |
| Sidestepping when the straight jump is possible | The sidestep is only allowed when a wall (or the board edge) is directly behind the opponent's pawn. |
| Moving and placing a wall in one turn, or passing | Each turn is exactly one action. |
| Placing a wall on top of another wall | Walls may not overlap, even partly. |
| Crossing two walls at their middle | A horizontal and a vertical wall can't share a middle point. |
| Placing an 11th wall | Each player has 10 walls. |
| Sealing a pawn in | Every player must keep at least one route to their goal edge. |
| Moving or taking back a placed wall | Walls are permanent. |
Overlapping walls
Crossing walls
Jumping through a wall
Quick rules summary
- Two players, a 9×9 board, one pawn each on the middle square of opposite edges, 10 walls each.
- Win by being first to reach any square of the opposite edge.
- Each turn: move your pawn one square or place one wall.
- Pawns step up, down, left or right, never through walls.
- Neighboring pawns with no wall between them: jump to the square behind the opponent. If a wall is behind them, step to their left or right instead.
- A wall is 2 squares long, can't overlap or cross another wall, and is permanent.
- No wall may leave any player without a route to their goal edge.
- With no walls left, you can only move.
Put the rules into practice.
The board highlights your legal moves and explains why a wall isn't allowed, so you can learn as you play.
These rules follow the official Gigamic rulebook (Quoridor, designed by Mirko Marchesi). The rulebook is silent on a few edge cases, and there this site's game applies the conventions marked above: the board edge acts like a wall behind a jumped pawn, and pawns are ignored by the route check. Quoridor Online is independent and not affiliated with Gigamic or the designer.