The position of Game Master (ゲームマスター Gēmumasutā?) gives one the ability to craft a tale using a game board. This position is held by a Witch/Sorcerer and the game board is Rokkenjima, specifically, from October 4th to October 5th of 1986. When creating a tale, the Game Master must always avoid creating a Logic Error or the game will instantly be destroyed.

There are/were other game boards than Rokkenjima in the Umineko universe, according to several other witches.

Known Game Masters