4 Acts

Since Act 2 is the longest of 3 acts, many writers split Act 2 into 2 smaller acts. They feel writing is easier when the middle act is divided in 2 parts the same length as Act 1 and Act 3. Instead of Act 2, the smaller acts are Act 2a and Act 2b. This doesn’t change 3-act structure. It’s a technique that writers use to think about segments of story, in a way that makes Act 2 easier to write, because it is planned in smaller parts.

4 Part Structure

When 4 acts are used, some writers prefer the word "Part" instead of "Act". For those folks, "Part 2" is a better name than "Act 2a", or "the first half of the second act."

Table 1. Acts vs. Parts
Act	Part
Act 1	Part 1
Act 2a	Part 2
Act 2b	Part 3
Act 3	Part 4

Structure is the writer’s map, ensuring that stories flow in a way that feels natural and engaging.

Don’t get caught up in the number of acts, or what they’re called. Whether it’s a short film, a TV show, or a novel, the essence of storytelling remains the same. It’s about taking your audience on a journey, one that feels coherent and complete. By understanding the basic framework that underpins all great stories, you can craft your own narratives with confidence, knowing you’re following a path laid down by generations of storytellers before you.