Chalice

From Itch.io page: Chalice is a collaborative storytelling game about a party of Arthurian knights searching for the Holy Grail. It requires one Chronicler to moderate the game and portray the perils of the world, and one or more players to portray the knights. A game of Chalice takes around 3-4 hours. The game tells the story of the physical and spiritual descent of the knights as they quest for, and ultimately fail to find, the Grail. The knight’s quest is a doomed one of chivalric virtue, undone by their own fatal flaws and moral shortcomings.