Epic win

I'm not sure it should be possible even? That or it's really simple.

Not exactly simple; you have to be building something with a minimal amount of complexity. But if you are, there's a significant chance of creating something that's accidentally Turing Complete. Much of the time, the fact that something is unintentionally Turing Complete is a minor matter of nerd interest because there's no way to do anything useful with it - who's going to exploit Magic: The Gathering's computational potential? Sometimes, though, it creates a major security flaw.