Actus primus

Actus primus is a fancy Latin term that means "first act." Imagine a play or a story with many different parts to it, kind of like a big puzzle. The actus primus is the very first part or piece of that puzzle.

Think of it like building a big Lego castle. You have a lot of different pieces, but you have to start with the base or the foundation first. The actus primus is like that base - it's the beginning of the story or the play, and it sets the stage for everything else that happens.

Sometimes the actus primus is really important and sets the tone for the rest of the story. Maybe it introduces the main characters, or tells us where the story takes place. Sometimes it's not as important, but it's always the first part of the story, so it's worth paying attention to.