Gambler's Transformations

What is the most you've ever lost in a card game? What's the most you've ever won? This is a story about gambling, but not with money. In this story, people are betting with changes to themselves.

A magical game set has appeared. Whether that's a deck of cards, a set of poker chips, an app for betting on sports, or a new game entirely. Players of this game make bets by saying a change they are offering. That can be a change to their body, mind, history, or anything about them. The value of that bet is decided by the game, then when the game ends, any losers have their bets come true.