Oh man this is a fun direction for There Is No Outside. Also, I'm so down for using a Ouija board to resolve conflict.
It really does feel like an AU (non-D&D) proto-RPG structure that could have existed. It's got that "if the outcome is unclear, roll dice, higher result gets what they want" feeling. I've always felt that there's something fundamentally different about using a shared object (one deck of cards, a ouija board, w/e) for all players to determine their outcomes. It has some cooperative/friendly/working together implications that dice just kind of don't have. It's subtle, but it's there.
And, as always, I love games that encourage us to contextualize violence in healthier ways. That is, not artifically removing it from places where it might be (there is plenty of violence in real life, and in children), but just saying outright: Hey Maybe Don't Punch Everything Immediately. This is exactly in line with how I imagine it would have been handled in the AU of the thought-experiment, and is exactly how we handle things interpersonally irl. There is power in just saying "Be better."
Thanks for the game! There Is No Outside is proving a pretty badass platform to build on.