Gess is a strategic board game

Board game

A board game is a game which involves counters or pieces being moved on a pre-marked surface or "board", according to a set of rules. Games may be based on pure strategy, chance or a mixture of the two, and usually have a goal which a player aims to achieve...

 for two players, involving a grid board and mutating pieces. The name was chosen as a conflation

Portmanteau word

A portmanteau or portmanteau word is a blend of two words or morphemes into one new word. A portmanteau word typically combines both sounds and meanings, as in smog, coined by blending smoke and fog. More generally, it may refer to any term or phrase that combines two or more meanings...

 of "chess

Chess

Chess is a two-player board game played on a chessboard, a square-checkered board with 64 squares arranged in an eight-by-eight grid. It is one of the world's most popular games, played by millions of people worldwide at home, in clubs, online, by correspondence, and in tournaments.Each player...

" and "go

Go (board game)

Go , is an ancient board game for two players that originated in China more than 2,000 years ago...

". It is pronounced with a hard "g" as in "go", and is thus homophonous

Homophone

A homophone is a word that is pronounced the same as another word but differs in meaning. The words may be spelled the same, such as rose and rose , or differently, such as carat, caret, and carrot, or to, two, and too. Homophones that are spelled the same are also both homographs and homonyms...

 with "guess".

Gess was created by the Puzzles and Games Ring of The Archimedeans, and first published in 1994 in the society's magazine Eureka. It was popularized by Ian Stewart

Ian Stewart (mathematician)

Ian Nicholas Stewart FRS is a professor of mathematics at the University of Warwick, England, and a widely known popular-science and science-fiction writer. He is the first recipient of the , awarded jointly by the LMS and the IMA for his work on promoting mathematics.-Biography:Stewart was born...

's Mathematical Recreations column in the November 1994 issue of Scientific American

Scientific American

Scientific American is a popular science magazine. It is notable for its long history of presenting science monthly to an educated but not necessarily scientific public, through its careful attention to the clarity of its text as well as the quality of its specially commissioned color graphics...

.

Rules

• Gess is played on a grid of 18 × 18 squares.
• Two players, "Black" and "White", each have 43 stones of their colour on the board in the starting configuration.
• Starting with Black, players take turns moving a piece on the board. A move must always change the stone configuration on the board. There is no passing.
• A piece consists of a 3 × 3 grid of squares, at least one of which must exist on the board. Only stones of one colour may be in the grid. There must be at least one stone on the eight squares around the central square.
• A piece can only be moved by the player whose stones are inside the grid.
• The 3 × 3 grid is termed the footprint of the piece. Each piece can move as determined by the stones in its footprint:
  • The central square determines the extent of the piece's movement. If the square is unoccupied, it may move up to three spaces; if it is occupied by a stone, it may move any number of spaces.
  • Each of the eight surrounding squares determines the directions the piece can move. If a square has a stone, the piece can move in the direction indicated by the square's location relative to the central square; if a square is unoccupied, the piece cannot move in that direction.
• As a piece moves, all of the stones in its footprint move in unison.
• When the footprint of a piece coincides with any other stones on the board, those stones are removed from the board and the move ends.
• If the footprint moves partially out of the board, the move ends. The stones of the piece which are on a square that has moved out of the board are removed.
• A move also may end before any stone is removed.
• A ring is any piece consisting of eight stones around an empty central square.
• The game object is to be the only player with a ring piece on the board: when, at the end of any turn, a player has no ring pieces on the board, that player loses the game. If neither player has a ring piece, the player who has just moved loses.

Equipment

A go

Go (board game)

Go , is an ancient board game for two players that originated in China more than 2,000 years ago...

 set is one easy way to assemble the equipment needed for gess. The 19 × 19 line grid is simultaneously an 18 × 18 grid of squares, and the starting position needs only 43 each of the black and white stones.

Influences

The rules describe a highly variable set of pieces, which will often change every turn. In total there are 510 possible sets of a footprint; however, the starting position uses these rules to emulate chess

Chess

Chess is a two-player board game played on a chessboard, a square-checkered board with 64 squares arranged in an eight-by-eight grid. It is one of the world's most popular games, played by millions of people worldwide at home, in clubs, online, by correspondence, and in tournaments.Each player...

 pieces: king

King (chess)

In chess, the king is the most important piece. The object of the game is to trap the opponent's king so that its escape is not possible . If a player's king is threatened with capture, it is said to be in check, and the player must remove the threat of capture on the next move. If this cannot be...

, queen

Queen (chess)

The queen is the most powerful piece in the game of chess, able to move any number of squares vertically, horizontally, or diagonally. Each player starts the game with one queen, placed in the middle of the first rank next to the king. With the chessboard oriented correctly, the white queen starts...

, bishop

Bishop (chess)

A bishop is a piece in the board game of chess. Each player begins the game with two bishops. One starts between the king's knight and the king, the other between the queen's knight and the queen...

, rook

Rook (chess)

A rook is a piece in the strategy board game of chess. Formerly the piece was called the castle, tower, marquess, rector, and comes...

 and pawn

Pawn (chess)

The pawn is the most numerous and weakest piece in the game of chess, historically representing infantry, or more particularly armed peasants or pikemen. Each player begins the game with eight pawns, one on each square of the rank immediately in front of the other pieces...

in this order R - B - Q - K - B - R in the last row (black's view) and 6 pawns in the next row.
The game objective, to remove the opponent's "ring" (described as a piece that moves like a chess king) also mimics that of chess.

Notation

The rows are named 2 to 19 (1 and 20 being outside the grid), and the files are named b to s (a and t again being outside the grid).

A move is notated by noting the place of the centre of the footprint at the beginning of a move and its place at the end of the move.

External links

• Gess the Game, original article at the online Eureka archive
• GESS -- a New chess/go variant, Gess @ chessvariants.com with links to a java applet to play Gess