City Square Off challenges two players to each build a well-designed city that doesn't spill over the boundary lines that govern play.Each player starts with a 9x9 playing area that has a different cityscape starter tile in the middle of it and a set of 21 city tiles. Game play takes place simultaneously, with one player turning over a shape card – each showing a Tetris-style arrangement of squares that matches one of the city tiles – and both players then adding the matching tile to their cities.Tiles must be placed with at least one edge adjacent to the starter tile or another tile in play. If a player would be forced to go outside the 9x9 city grid, that player loses; if both players would lose on the same turn, then the player with the largest contiguous group of open spaces is dubbed master city planner and wins the game.