---
title: "StarCraft II thirds rule"
description: "Design mantra adapted from Sid Meier for making a sequel to a game players call perfect."
canonical: https://tomsharman.com/bookshelf/play-nice/starcraft-ii-thirds-rule/
updated: 2026-11-03
---

# StarCraft II thirds rule

> Design mantra adapted from Sid Meier for making a sequel to a game players call perfect.

Jason Schreier's framework, from Play Nice, pp. 110 to 199.

Framework 7 of 15 from [Play Nice](https://tomsharman.com/bookshelf/play-nice/index.md) by Jason Schreier. Category: Personal brand.

## The steps

1. **One third returns.** Keep a third of the original units unchanged.
2. **One third modified.** Adjust a third of the units.
3. **One third new.** Introduce a third as brand new units.

## Where it comes from

From chapter: PART TWO: FALL, pp. 110–199

## The animation

24 seconds, 4:5, no sound.

- MP4: https://tomsharman-downloads-006143767029.s3.eu-north-1.amazonaws.com/downloads/bookshelf/play-nice/starcraft-ii-thirds-rule.mp4
- MP4, dark: https://tomsharman-downloads-006143767029.s3.eu-north-1.amazonaws.com/downloads/bookshelf/play-nice/starcraft-ii-thirds-rule-dark.mp4
- Still: https://tomsharman-downloads-006143767029.s3.eu-north-1.amazonaws.com/downloads/bookshelf/play-nice/starcraft-ii-thirds-rule.png
- Still, dark: https://tomsharman-downloads-006143767029.s3.eu-north-1.amazonaws.com/downloads/bookshelf/play-nice/starcraft-ii-thirds-rule-dark.png