Hex is a strategy game invented by Piet Hein in Denmark in 1942, and later rediscovered and popularized by John Nash. It has simple rules, yet offers a surprising amount of strategic depth. The game can't end in a tie, and when playing without the swap rule, the first player is known to have a theoretical winning strategy, although it is not known what that strategy is.
The board has two red edges and two blue edges. The goal for each player is to connect their two edges with stones of their color.
Players take turns placing a stone of their own color on the board, with Red going first. Stones can be placed on any empty cell and once placed, they are never moved or removed.
The swap rule
To balance the game, the swap rule is used. After the first player opens with a red stone, the second player has the option to "swap," or steal the opponent's first move. In this case, Red's initial stone is replaced by a blue stone and mirrored about the long diagonal. After this, it is Red's turn.
The game ends when one of the players has connected their edges with a path of stones of their color. When it is clear to both players who will win, it is customary for the losing player to resign.
Game options and interface
The game can be played on boards of different sizes. The 6x6 board is designed for beginners, the 11x11 board is a classic size, and the 12x12, 13x13, 14x14, and 15x15 boards are larger options for more experienced players. The 6x6 board size is only available in training mode.
Making moves and swapping
To make a move, click on an empty cell. To guard against accidental misclicks, you must confirm each move by clicking on the stone a second time, or by using the "confirm" or "cancel" buttons above the play area. On the second move of the game, you have the option to swap. To do so, click on the "swap" button above the play area. If you do not want to swap, simply make a normal move.
Resigning and passing
Players can resign at any time, whether or not it is their turn. The resign button is found in the "additional game controls" menu, which is marked by three dots "..." in the upper right corner of the play area. Passing is rarely done in Hex, as it never benefits a player. However, the option to pass is found in the "additional game controls" menu, which is marked by three dots "..." in the upper right corner of the play area. Three passes in a row are not permitted, so if both players have passed, the next player must make a proper move.
The default shades of red and blue used in Hex can be difficult to distinguish for colorblind people. To compensate for this, there is a game display option for color blindness in the Options menu below the game board.