# Board

## Board dimensions

The Hex board is composed of hexagons, called hexes or cells, arranged in an n×n rhombus, where n is an integer greater than zero. Thus, Hex can be played on boards of different sizes. Currently, 11×11, 13×13, and 19×19 are the most common board sizes.

Less commonly, Hex can also be played on non-rhombic boards of size n×m. However, in that case, one of the players has an easy winning strategy, so non-rhombic boards typically only appear in Hex puzzles or in certain kinds of handicap games.

## Corners

The board has four corners. Two of them are acute corners and two of them are obtuse corners. In the above illustration, a1 and g7 are the acute corners, and a7 and g1 are the obtuse corners.

## Edges

The four edges of the board are colored with two colors, in such a way that parallel edges have the same color. In this Wiki, the color used by the first player is red, and the color used by the second player is blue. The edge coloring follows the order red-blue-red-blue, when traversing the edges counterclockwise starting from an acute corner. This means that if an acute corner is at 10 o'clock, the top and bottom edges are red and the left and right edges are blue.

Another common coloring scheme is black (for the first player) and white (for the second player). In any case, the orientation of the board stays the same, with the first player's edges in place of red, and the second player's edges in place of blue.

## Ranks, files, and coordinates

A rank or row of the board is a line of hexes parallel to a red (or first player) edge. Ranks are numbered 1,2,3,... A file or column is a line of hexes parallel to a blue (or second player) edge. Files are lettered a,b,c,... Each hex is identified by its coordinates, which are given by file and rank, for example, a1, b5, d3. The coordinates are always arranged so that a1 is an acute corner.

In the following diagram, the blue cells are on the c-file, the red cells are on the 4-rank, and the grey cell is c4.

## Diagonals

Each board of size n×n has a short diagonal and a long diagonal. In the following diagram, the short diagonal is red, the long diagonal is blue, and the center of the board is on both diagonals (grey).

## Areas of the board

The board can be roughly divided into 9 areas: two acute corner areas (A), two obtuse corner areas (B), two areas near red edges (C), two areas near blue edges (D), and the center (E).

On the 7×7 board above, these areas are very small and close to each other. But on larger boards, these areas become more pronounced and important. For example, there is an entire theory devoted to corner play in Hex.

## Referring to parts of the board

When discussing and commenting games, it is common to refer to the various areas of the board as the "upper left" corner, the "bottom" edge, etc. For boards that are oriented with the a1 corner at 9 o'clock, some people also use terms such as the "south-west" edge.

However, one should keep in mind that not all players orient their boards the same way. Some internet game sites have the a1 corner at 8 o'clock, 9 o'clock, or 10 o'clock. Some software permits players to rotate the board to their individual preferences (and not surprisingly, different players actually do have different preferences!). Physical game boards can certainly be rotated and are usually looked at from different directions by the two players. Therefore, when commenting games, it is preferable to refer to parts of the board as the "a1-corner", the "11-edge", the "a11-corner area", and so on.

On this Wiki, the boards are (almost) always oriented with the a1 corner at 10 o'clock, and when terms such as "top", "bottom", "left", and "right" are used on this Wiki, they always refer to this orientation.