Played on the London Underground map, the aim of this game is to be the first player to reach Mornington Crescent. Players take turns to move their pawns around the board, optionally adding (initially meaningless) tokens to stations they visit. At any time, a player may spend one of their two veto chips to veto another player's move, announcing a new restriction under which that move is illegal (such as "players may not move more than six stations in a turn"). In doing so, the players gradually build a set of restrictions for how the game is to be played. Play continues until a player is able to reach Mornington Crescent without having their move vetoed. By framing all discussion of additional rules as mere "reminders" of a deeper, undisclosed ruleset, the game appears to an audience to be a fully-formed boardgame rather than something that the players are largely inventing on the fly.