Okay, so imagine you and your friends are playing a game like Red Rover. There are rules that everyone agreed to follow, like holding hands and saying "Red Rover, Red Rover, send (friend's name) over". But sometimes, someone might break the rules and try to run through without holding hands, which isn't fair.
Now, let's apply this to countries and international laws. Just like in Red Rover, there are rules that countries have agreed to follow, called international laws. But sometimes, a country might try to do something that breaks those rules, which can hurt other countries or people.
That's where peremptory norms come in. These are really important laws that no country is allowed to break, no matter what. Just like in Red Rover, where you can't go through without holding hands, countries can't do things like torture people, use chemical weapons, or have slavery. If a country does break one of these big rules, other countries can work together to stop them.
So, peremptory norms are super important rules that everyone has to follow, just like in a game of Red Rover where everyone has to hold hands to keep things fair.