Four-dimensional chess, or 4-D chess, was a Time Lord variant of the Earthly game of chess which was "very popular" on Gallifrey. (GAME: "Skill Explanations" [+]Part of The Iytean Menace, J. Andrew Keith, The Doctor Who Role Playing Game (FASA, 1985).)
Rollo was a skilled 4-D chess player. (GAME: "Player Characters" [+]Part of The Iytean Menace, J. Andrew Keith, The Doctor Who Role Playing Game (FASA, 1985).)
The Entity considered four dimensional chess to be an "elegantly simple" game. (PROSE: Games [+]Warwick Gray, Brief Encounters (Marvel Comics UK, 1992). Page 22.)
Nature[]
The game shared the basic rules of Earth chess, (GAME: "Skill Explanations" [+]Part of The Iytean Menace, J. Andrew Keith, The Doctor Who Role Playing Game (FASA, 1985).) including the use of chess pieces such as Kings, (PROSE: Games [+]Warwick Gray, Brief Encounters (Marvel Comics UK, 1992). Page 22.) but could be played on "multiple levels" (GAME: "Skill Explanations" [+]Part of The Iytean Menace, J. Andrew Keith, The Doctor Who Role Playing Game (FASA, 1985).) or on an ever-increasingly fast translucent sphere whose board pattern changed over the course of the game, which resulted in the "structure of the conflict" being rearranged every time. (PROSE: Games [+]Warwick Gray, Brief Encounters (Marvel Comics UK, 1992). Page 22.) The pieces were capable of time travel, (GAME: "Skill Explanations" [+]Part of The Iytean Menace, J. Andrew Keith, The Doctor Who Role Playing Game (FASA, 1985)., PROSE: Games [+]Warwick Gray, Brief Encounters (Marvel Comics UK, 1992). Page 22.) being able to dematerialise from the board and materialise elsewhere on later turns of the games, (GAME: "Skill Explanations" [+]Part of The Iytean Menace, J. Andrew Keith, The Doctor Who Role Playing Game (FASA, 1985).) as well as moves occurring in the future being twist back on themselves to affect moves made in the present. The pieces also increased in number over the course of a game. (PROSE: Games [+]Warwick Gray, Brief Encounters (Marvel Comics UK, 1992). Page 22.)
Known challenges[]
The Mandarin and the Entity once played a match in the non-world where the Entity was banished. The game was played until the Mandarin began to lose, so he strategically manoeuvred the game to result in a stalemate. (PROSE: Games [+]Warwick Gray, Brief Encounters (Marvel Comics UK, 1992). Page 22.)