unity-architecture-patterns

name	unity-architecture-patterns
description	Unity Design Patterns

Unity Design Patterns

Use this skill when choosing, implementing, or combining design patterns in Unity. Covers SOLID principles and 11 patterns with RC racing examples, Unity-specific implementation details, advanced combination techniques, and guidance on when each pattern helps vs. when it is overkill.

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SOLID Principles

Design patterns are most effective when grounded in SOLID. These five principles guide when and how to apply patterns in Unity.

"Don't force principles into your scripts for the sake of it. Let them organically work into place through necessity." Also keep KISS and DRY in mind -- apply SOLID where it reduces complexity, not where it adds ceremony.

Single Responsibility

Each class/MonoBehaviour is responsible for one thing. A RaceManager manages race state -- it does not also handle UI updates or audio. If a class has multiple reasons to change, split it.

Open-Closed

Classes open for extension, closed for modification. Use ScriptableObjects and interfaces to add new behavior without modifying existing code. Example: new surface types via SurfaceData SO assets, not by adding cases to a switch statement in the physics system.

Liskov Substitution

Derived classes must be substitutable for their base. If Vehicle has a Drive() method, every subclass must honor that contract. Do not throw NotImplementedException in overrides -- that violates the contract callers depend on.

Interface Segregation

Do not force classes to implement methods they do not use. Split large interfaces: IDamageable, IRepairable, IResettable -- not one IVehicle with 20 methods. Each interface should represent a single capability.

Dependency Inversion

High-level modules depend on abstractions, not concrete implementations. Inject dependencies via constructor, [SerializeField], or interfaces -- never FindObjectOfType. This is why our project forbids singletons and Find() calls (see coding standards).

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Pattern Catalog

Pattern	Purpose	RC Racing Example
Observer	Decouple event senders from receivers	OnLapComplete, OnCheckpointReached
State	Manage complex object states with transitions	Vehicle: Idle, Accelerating, Braking, Airborne, Crashed
Factory	Create objects without exposing concrete types	Track obstacle spawning, vehicle configuration
Command	Enable undo/redo, replay, queued actions	Track editor undo/redo for obstacle placement
MVP	Separate UI from game logic	Race HUD presenter wiring model to view
MVVM	Automatic data binding for complex UIs	Settings screen, garage/tuning UI
Strategy	Swap algorithms at runtime	Surface physics: grip/friction per terrain type
Flyweight	Share data across many similar instances	Track segments: same geometry, different positions
Dirty Flag	Skip expensive recalculations	Recalculate race standings only when positions change
Object Pooling	Reuse objects to avoid GC spikes	Tire smoke particles, dust effects, sound effects
Singleton	ANTI-PATTERN -- globally accessible single instance	Shown for reference; use alternatives below

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Source References

Resource	URL
Free e-book (100 pages)	https://unity.com/resources/games/level-up-your-code-with-game-programming-patterns
GitHub sample project	https://github.com/Unity-Technologies/game-programming-patterns-demo
Unity Learn course (Unity 6)	https://learn.unity.com/course/design-patterns-unity-6
SOLID talk (Unite Austin 2017)	https://www.youtube.com/watch?v=eIf3-aDTOOA

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Related Skills

Skill	Relationship
unity-csharp-mastery	C# lifecycle, attributes, naming conventions, anti-patterns
unity-scriptable-objects	Extended SO patterns: event channels, runtime sets, SO-based enums, delegate objects
unity-state-machines	Advanced FSM: hierarchical states, Animator integration
unity-composition	Component architecture, dependency injection, interfaces
unity-performance-optimization	Profiling, batching, GC reduction, LOD
unity-testing-patterns	Unit testing patterns for these architectures
unity-project-foundations	.asmdef setup, folder structure, YAML serialization, workflow optimization
unity-3d-world-building	NavMesh, terrain, level design, AI navigation
unity-editor-scripting	Custom inspectors for SO-heavy architectures
unity-ui-toolkit	UXML/USS for MVC/MVVM data binding

Topic Pages

• Observer Pattern
• Quick Reference: Which Pattern Do I Need?