Okay kiddo, imagine you have a toy car and your friend has a toy truck. You both decide to play together with both toys, so you merge them together to make one big toy car-truck.
Now, let's apply this idea to criminal law. The merger doctrine says that when someone commits a crime that includes a lesser crime, the lesser crime is "merged" into the greater crime. It's like putting your toy car into your friend's toy truck and calling it a car-truck.
For example, let's say someone broke into a store and stole some merchandise. This is a crime called burglary. But if they also broke a window to get in, that's another crime called criminal mischief. So in this case, the lesser crime of criminal mischief would be merged into the greater crime of burglary.
This matters because if someone is convicted of both crimes separately, they could potentially face double punishment - kind of like getting in trouble twice for the same thing. But because of the merger doctrine, they can only face punishment for the greater crime.
So just like merging your toy cars and trucks together, the merger doctrine merges lesser crimes into greater crimes to simplify the punishment process in criminal law.