Agon (or queen's guards or royal guards) is a strategy game invented by Anthony Peacock^[1] of London, and first published in 1842.^[2] It is a two-player game played on a 6×6×6 hexagonal gameboard, and is notable for being the oldest known board game played on a board of hexagonal cells.^[3]

Each player has one queen and six guards. Players determine who moves first, then turns alternate. On each turn, a player moves one of his pieces. The object of the game is to be first to maneuver one's queen to the central hex (the throne) at the center of the board, and surround her with all six of her guards.

• In the original rules,^[2][1] an alternative opening sequence is described: The game starts with only queens, in opposite corners of the board. Players place their guards, one per turn, on any vacant board cells (except the throne). After all twelve guards have been placed, the game proceeds under normal rules.
• A different capture rule for queens is described in The Way to Play: the owner must move his captured queen "to any vacant square that his opponent requires".^[4]
• In the Book of Games by Jack Botermans, the rule for capturing states that a player's piece is 'blocked' when between two of their opponent's pieces "in the same ring".^[5]
• In a variant used by the Penthalon Institute, called Queens and Guards, a captured piece must move back to an adjacent hexagon within the next outer band.

In the Victorian era, sets were sold by wood turner Thos Sherwin, and Jaques and Son.^[3] Game tables from 18th-century France have been observed with a game board which is almost certainly Agon.^[6] It is now thought, however, that the Agon boards were later additions.^[3] Versions of Agon are published by Waddingtons Games, House of Marbles and Kruzno.

Eugene Provenzo's Favorite Board Games You Can Make and Play gives detailed plans for making Agon sets.^[7]

• List of board games
• Tabletop game