Grid chess is a

chess variant A chess variant is a game related to, derived from, or inspired by chess. Such variants can differ from chess in many different ways. "International" or "Western" chess itself is one of a family of games which have related origins and could be co ...

invented by Walter Stead in 1953. It is played on a ''grid board''. This is a normal 64-square

chessboard A chessboard is a used to play chess. It consists of 64 squares, 8 rows by 8 columns, on which the chess pieces are placed. It is square in shape and uses two colours of squares, one light and one dark, in a chequered pattern. During play, the bo ...

with a grid of lines further dividing it into larger squares. A single additional rule governs Grid chess: for a move to be legal, the piece moved must cross at least one grid line. Grid chess is also used in

chess problems A chess problem, also called a chess composition, is a puzzle set by the composer using chess pieces on a chess board, which presents the solver with a particular task. For instance, a position may be given with the instruction that White is to ...

Description

Various arrangements of the grid have been tried, but the original, and by far the most popular, is that illustrated, which divides the board into sixteen 2×2 squares. In the sample position,

White White is the lightest color and is achromatic (having no hue). It is the color of objects such as snow, chalk, and milk, and is the opposite of black. White objects fully reflect and scatter all the visible wavelengths of light. White on ...

can play either a3 or a4, but cannot move the b-pawn. Black cannot play ...Bd5 but can play any other bishop move – to put the bishop on d5, it will take two moves (for example, first ...Ba8, then ...Bd5). The white king is not in check from the queen, but would be, if the queen were to take a step back with ...Qe3. The white king cannot take the queen, although the white knight can. The black king, on the other hand, ''is'' in check from the rook on c8. Black cannot escape check as in standard chess with ...Ke7 or ...Kf7, as these moves do not cross a grid line. Black can play ...Kd7, however, and also ...Kd8, bringing the king into the same large square as the rook.

Example problem

It is possible to play entire games under Grid chess conditions, and a number of chess problems using Grid chess rules have also been composed. The one shown won first prize in the first Grid chess problem tournament. It is by H. Ternblad and was published in ''Fairy Chess Review'', 1954. It is a

helpmate A helpmate is a type of chess problem in which both sides cooperate in order to achieve the goal of checkmating Black. In a helpmate in ''n'' moves, Black moves first, then White, each side moving ''n'' times, to culminate in White's ''nth'' mov ...

in four (Black moves first and cooperates with White to

checkmate Checkmate (often shortened to mate) is any game position in chess and other chess-like games in which a player's king is in check (threatened with ) and there is no possible escape. Checkmating the opponent wins the game. In chess, the king is ...

him within four moves). The solution: :1. Ke2 Bc4+ 2. Kd3 This brings the king into the same large square as the bishop, and so escapes the check. :2... Bxb5+ Withdrawing the bishop over a grid line gives check again. :3. Ke4 Bc6+ 4. Kd5 Two kings can coexist next to each other so long as they are in the same large square. :4... Bxb7 This problem displays attractive correspondence between the paths taken by the king and bishop. It is worth noting the zigzagging path the black king must take to reach d5: the straightforward route Kd1–d2–d3–d4–d5 is not possible because two of the moves do not cross grid lines, and Kd1–e2–e3–d4–d5 is not possible because on d4 the king is checked by White's king.

References

* *

External links

Chess Composition Microweb
Grid chess problems

a simple program by Ed Friedlander (

Java Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's List ...

) {{Chess variants, state=collapsed Chess variants Chess problems Fairy chess 1953 in chess Board games introduced in 1953