carte blanche

if someone has been given carte blanche, it means that the person is free to do or say whatever they please.

John: So you are saying the only rule is to get the ball to the target?
Alice: Yep! There are no other rules.
John: I don’t see how this game could possibly work.
Alice: Think of it this way. All the players have carte blanche to do whatever they think will help them get the ball to the target

John: So punching is allowed?
Alice: Anything.