In the land of Earthshine, a game of luck has been passed down from generation to generation, evolving as the years went on. Today, we pass that game to you, allowing you to make it your own.
Players use polyhedral dice (d4 through d20, which they must provide), and a coin (or d2), starting with the d20, to attempt to roll successfully under the next die type (under a 12 on a d20 for example) to gain the new dice type. They continue rolling each die type, attempting to add the next lower die until they decide to stop, at which point they can try to get a gem by rolling all of their accumulated dice.
A player wins if they collect the moon token (which they get if the earn the d2/coin and successfully flip heads) and keep it until the start of their next turn, or if they earn 4 gems.