unity-project-foundations

name	unity-project-foundations
description	Unity Project Foundations

Unity Project Foundations

Use this skill when setting up project folder structure, configuring assembly definitions, managing packages, or establishing code style and version control conventions for a Unity project.

Editor Settings Checklist

Before first commit, verify these settings:

Setting	Location	Required Value
Serialization Mode	Editor Settings	Force Text
Visible Meta Files	Editor Settings	Visible (version control mode)
Default Behavior Mode	Editor Settings	3D or 2D (match your project)
Color Space	Player Settings	Linear (for PBR) or Gamma
Scripting Backend	Player Settings	IL2CPP (for builds) or Mono (for dev)
API Compatibility	Player Settings	.NET Standard 2.1 or .NET Framework
Enter Play Mode Settings	Project Settings	Enabled, with Domain/Scene Reload disabled for fast iteration

Enter Play Mode Settings

Edit -> Project Settings -> Editor -> Enter Play Mode Settings.

When enabled with "Reload Domain" unchecked, entering play mode is near-instant. But you must handle static state manually:

public class ScoreManager : MonoBehaviour
{
    private static int _totalScore;

    // Reset static state when entering play mode without domain reload
    [RuntimeInitializeOnLoadMethod(RuntimeInitializeLoadType.SubsystemRegistration)]
    private static void ResetStatics()
    {
        _totalScore = 0;
    }
}

Rule: Every class with static fields needs a [RuntimeInitializeOnLoadMethod] reset method when using fast enter play mode. Without it, static state bleeds between play sessions.

Common Mistakes

1. No assembly definitions -- every change recompiles everything, 30-second iteration time
2. Binary serialization mode -- impossible to diff or merge scenes
3. No .gitignore -- Library/ (10+ GB) gets committed, repo becomes unusable
4. No Git LFS -- textures and models bloat the repo permanently (git history keeps every version)
5. Scripts in Assets root -- no namespace boundaries, everything depends on everything
6. Using Resources folder liberally -- everything in Resources is included in the build
7. No .editorconfig -- inconsistent code style, noisy diffs from formatting changes
8. Skipping Enter Play Mode Settings -- waiting 5-10 seconds to test every change

Topic Pages

• Recommended Folder Structure
• Build Pipeline Basics