In CryptoLeaders, players collect and trade historical figures as smart contracts on the Ethereum blockchain technology.
Each card is unique so when you buy a historical figure you own it. The only way for a player to purchase it from you is to pay up to double the price. The ownership will then be automatically transferred to the buyer.
We run the game on the Ethereum blockchain so the only way to purchase a card is using Ether. You can purchase Ether directly on Metamask if you are an US citizen or on an exchange for everyone else in the world.