Shibumi (the game) is the subject of the Shibumi Challenge, an upcoming experiment in automated game design.

The overall aim is to compare the dynamics of evolutionary versus Monte Carlo search methods for game design, and to gauge the usefulness of the computer as a creative collaborator in the game design process.

The ideal game system to test these ideas would be:

• Tightly constrained and with a small, clearly defined rule set.
• Simple enough that most of the rule combination space could be searched.
• Complex enough to provide a range of interesting games.
• Small enough that its board state would fit into a single integer (for efficient implementation).
• Novel enough that its search space was largely unexplored.

While I was looking for such a system, abstract gamer Tom Gilchrist mentioned a concept from Japanese aesthetics called shibui. Shibui objects balance simplicity with complexity; they may initially seem deceptively plain, but will reveal hidden depths and become more interesting the more time is spent with them.

— Cameron Browne @ BoardGameGeek

See also Shibui @ Wikipedia.