The rules are simple and straightforward, and they will be enforced — which is to say that, if you don't follow those rules, you will be punished.
An easy way to remember that enforced means "required" or "compelled" is to think of rules being "in force." If your mom or dad tells you that the house rules will be "in full force" while they're away at dinner, that means the rules will be enforced. And I think we can all agree that rules that aren't enforced are worse than useless. Failing to enforce them just teaches kids that there are no rules. That might be OK at home, but when they get out into the real world, where rules and laws are enforced, they'll be in for a rude awakening.
