“When in doubt, the rule of threes is a rule that plays well with all of storytelling. When describing a thing? No more than three details. A character’s arc? Three beats. A story? Three acts. An act? Three sequences. A plot point culminating in a mystery of a twist? At least three mentions throughout the tale. This is an old rule, and a good one. It’s not universal — but it’s a good place to start. – ”

–Chuck Wendig