diff --git a/docs/OnitamaGamePatterns.md b/docs/GamePatterns.md
similarity index 97%
rename from docs/OnitamaGamePatterns.md
rename to docs/GamePatterns.md
index c626602..eb91db8 100644
--- a/docs/OnitamaGamePatterns.md
+++ b/docs/GamePatterns.md
@@ -70,6 +70,7 @@ Register scenes in `App.tsx` via `<PhaserScene>`. Pass data via `data` prop.
 - **Type Imports**: Use `import type { Foo } from 'bar'` for type-only imports.
 - **Input Handling**: Use `this.add.zone()` for grid/cell-based input zones.
 - **Cleanup**: Always dispose `effect()` on `'destroy'`. Use `this.disposables.add()` for scene-level resources.
+- *Keep files short and focused**: Each file should have a single responsibility, and not exceed 200 lines.
 
 ## Common Pitfalls