No competition on Earth just allows "whatever happens, happens". Because at that point they're not competitions, they're death matches. Imagine if boxers could legally rabbit punch, or hit below the belt. There'd be no healthy competition left.

Hell, restrictions (perhaps paradoxically) usually INCREASE options. It's not like the competitive players choose which options or tactics are strongest. The game designers did that.

If there is one option that is wildly better than another, it will become the only option. Thus, decreasing the number of options to one.

And so, restrictions are made.