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
|Hanyū Furude||All of the story arcs in Higurashi no Naku Koro ni|
(according to Lambdadelta in the Dawn of the Golden Witch manga)