Octalion, an expansion for Heptalion, includes eight new domino-like tiles (with a new symbol) and a game board featuring a special board configuration that has the following properties: Each symbol is shown exactly 9 times. Each domino is shown exactly 3 times. There are exactly 72 squares; the same number of squares that compose the 36 tiles. The first board configuration with the above properties was found by Mark Tilford.