I did a whole line of third-party support material for Monte Cook’s Arcana Evolved. Most of these were straightforward splatbooks. But I did have a crazy idea. In the setting material, Monte had a throwaway line about a game called “Witch Stones”, which was “a strategy game played with a set of tiles bearing symbols”. I decided to design that game. It’s a quick little abstract game with significant strategy and random board setup to improve replay value.