Spire is a game that can be played with the Series: Shibumi game system. It uses a complete set with a 4×4 board, white, black, and red balls.
RulesThe board starts empty. Two players, White and Black, take turns placing a ball of their colour or a red ball either on an empty board hole or stacking on a 2×2 platform.
If a red ball is placed then the player must play another ball of their own colour in the same turn.
No single 2×2 square of ball locations may include more than 2 like-coloured balls.
Playing on a platform is only possible if the colour to be played is not used twice in the base.
Players must place a ball of their own colour during their turn. If there is no placement available (in the beginning of their turn or after a red ball was played) the current player loses the game immediately.
Included in the Shibumi Rule Book