"A new Minecraft server allows players in the blocky universe to compete against one another to find hidden treasure and receive a bitcoin reward"

Coindesk:

Known as SatoshiQuest, the challenge is to find the hidden loot within "vast Minecraft landscapes." Users pay $1 in bitcoin for an in-game life. Entry fees are collected and most will go towards a specific treasure wallet address, which is awarded to the player who finds the loot first.

In order to participate, users set up their own in-game wallet they can use to pay for lives and receive their winnings.