Sepulchasm

Sepulchasm was a board game played by Time Lords. It exercised psychic abilities. The game could be played by two people or solo. It dated back to the Old Time of Gallifrey. (PROSE: Cat's Cradle: Time's Crucible)

Rules
The board was a relief map of a mountain range set into a pedestal. The mountains held miniature models of organic houses (copies of the Great Houses, presumably). The houses were linked by a path which was divided into coloured squares. Each house had a playing piece with its own colour.

At the start of a game, each player would pick three of the pieces. Players took turns rolling an eight-sided die and their pieces would move across the paths according to the number rolled. When the die showed 45, the board would crack and split open, causing the players to exclaim, “Sepulchasm!” At this point the players would have to will their pieces to hover in the air over the board. The player who lost concentration and let his or her pieces fall into the chasm first would lose. (PROSE: Lungbarrow)

Behind the scenes
Sepulchasm has also been used as a swear word by various individuals. It generally seems to be the Gallifreyan equivalent of “Hell.” It is worth noting that the English word "sepulchre" means a tomb and "chasm" means a deep pit or yawning fissure in the earth, usually with the implication of immense depth or size. Hence, the word "Sepulchasm" may be meant to imply something along the lines of "the yawning fissure of the tomb"...a fitting description of a Hell.