Once Upon A Time is a game in which the players create a story together, using cards that show typical elements from fairy tales. One player is the Storyteller and creates a story using the ingredients on their cards. They try to guide the plot towards their own ending. The other players try to use cards to interrupt the Storyteller and become the new Storyteller. The winner is the first player to play out all their cards and end with their Happy Ever After card.

The third edition features multiple changes, including new artwork by Omar Rayyan, a new card set, and a simplified rulesheet.