Conventions

This page lists some proposed conventions for Hex games. These conventions concern the color of the players, who goes first, the orientation of the board, and the numbering of the positions on the board. However, unlike much older games such as Chess and Go, there are no generally agreed upon standard conventions for Hex, and different people, game sites, books, and computer programs sometimes use different conventions.

We distinguish two different classes of conventions: logical conventions are concerned with the abstract rules of Hex, irrespectively of how the players visualize the game, whereas physical conventions relate to the specific appearance of the game board. If the game is played remotely, for example on an internet game server or over email, each player can follow their own physical convention; for example, it is quite possible for each player to choose a different orientation of the board, or even different colors for the players. However, both players should follow the same logical conventions.

The need for conventions

There are several aspects of a game of Hex that are basically arbitrary and do not affect game play in an essential way. This includes the orientation (rotation and reflection) of the board, the colors of the players, who goes first, which edge belongs to which player, and how (if at all) the cells on the board are numbered. The same is true for other games as well; for example, the game of Chess would not change in an essential way if the white square were in the bottom left instead of the bottom right, if black went first instead of white, if the white queen started on a black square instead of a white one, if the ranks were lettered and the files numbered instead of the other way around, and so on. Nevertheless, it is expedient if all players follow the same conventions, so that, for example, everyone understands what it means to move a pawn from d2 to d4 without requiring further explanation.

Logical conventions

• The pieces are of two different colors: color 1 and color 2. The player who goes first uses color 1 for their first move. (They may later switch to color 2, if the second player invokes the swap rule).

• Cells are described by a letter and a number. Letters can be uppercase or lowercase. The cell A1 is in an acute corner of the board.

• The edge that the cells A1, B1, C1, etc, are adjacent to, and the edge that is opposite to it, are "color 1" edges. The edge that the cells A1, A2, A3, etc are adjacent to, and the edge that is opposite to it, are "color 2" edges.

• To win, the player who uses color 1 must make a connection between the two color 1 edges, and the player who uses color 2 must make a connection between the two color 2 edges.

Swapping:

• If the second player decides to swap, then the players change colors, not the pieces on the board. For example: Player 1 plays black on g4. Player 2 swaps. The board remains unchanged, i.e., the black piece remains at g4. The coloring of the edges also remains unchanged. Right after the swap, it is therefore player 1's turn to play a white piece.

With these conventions, a game can be unambiguously described by the board size and a sequence of moves that are either the name of a cell or "S" for a swap move. For example: g4 S f7 e7 describes a game in which player 1 plays color 1 at g4, player 2 swaps, player 1 plays color 2 at f7, and player 2 plays color 1 at e7.

Note that the logical conventions are purely symbolic. They do not depend on any particular board layout.

Physical conventions

Orientation of the board:

• The preferred convention for the orientation of the board is so that the cells A1, B1, A2 form a clockwise triangle in that order. In other words, if the board is rotated so that the acute corners are pointing east and west, then the northwest and southeast edges are the color 1 edges, and the northeast and southwest edges are the color 2 edges.

• There is no preferred convention for the rotation of the board. Indeed, players using a physical game board may freely move around the board and look at it from any angle they want. In computer hex, the most common conventions are the "diamond" shape, where the acute corners are pointing left and right, and the "flat" shape, where the color 1 edge is horizontal and the cell A1 is in the upper left corner. There is also the "flat II" shape, which is the flat shape upside down (i.e., with the opposite orientation; in this case, A1, B1, A2 form a counterclockwise triangle).

Colors:

• If the two colors are black and white, then black goes first, i.e., black is color 1 and white is color 2.
• If the two colors are red and blue, then red goes first, i.e., red is color 1 and blue is color 2.
• If the two colors are called V and H, then V goes first, i.e., V is color 1 and H is color 2. In that case, it is customary to orient the board so that the color 1 edges are horizontal, so that V and H must make a vertical and horizontal connection, respectively.

List of conventions used

	Acute	Edge	Swap	Mirror	Rotation	Black/red/V first
Browne	✓	✓	✓	✓	diamond	(✓)
Seymour	✓	✓	no	✓	✓	✓
Berge	✓	?	?	no	flat II	?
Hexy
Mohex
TRMPH
Board Game Arena
Little Golem
igGameCenter

Notes: Browne states that there is no universal convention for which color goes first, but uses the "black first" convention for all examples in the book.