What is a child explanation of oligarchy?

Oligarchy is when a small group of people has all the power and makes decisions for everyone else. It's like if only a few kids in a class got to decide what game to play at recess, while everyone else just had to go along with it. This small group might be rich, have special skills, or be really good at persuading others. So, instead of everyone having a say, just a few people control what happens.