Magic Coin

It looked like a novelty _Heads or Tails _coin

But it was magical. First, if the owner of the ring asked someone to call it, the person had to accept. Secondly, if the person called it correctly, he or she would be rewarded. If it was called incorrectly, he or she would lose something or something bad would happen. For example, you could tell a man "If you call it correctly, you will have incredible sexual stamina, but if it you call it incorrectly, you'll suffer from premature ejaculation." Or the owner could tell a woman: "Call it correctly, and your crush will ask you out. Call it incorrectly, and you'll completely humiliate yourself in front of your crush."

The winning offer must be something equally good to the bad of the losing offer and vice versa. For example. the owner of the coin could not say "Call it correctly, and you'll gain $5, but if you're wrong, you will be completely broke." Nor could you say, "Call it correctly, you'll become a billionaire, but if you're wrong, you'll lose 25 cents."