Default rule

A default rule is like a pre-decided way of doing something when we don't have any specific instructions on how to do it. Imagine if we were playing a game with our friends and they didn't tell us what the rules were. We might get confused about what to do next. But if we have a default rule, like whoever rolls the highest number goes first, then we can follow that rule instead. It's like having a backup plan in case we don't know what to do. Default rules are especially helpful when we want to make sure everyone follows the same rules, even if we forgot to tell them all the details.