unity-game-loop

Game Loop & Progression -- Design Translation Patterns

Prerequisite skills: unity-state-machines (session FSM), unity-game-architecture (events, Service Locator, bootstrap), unity-data-driven (SO configs for difficulty/pacing)

Claude's most common gameplay failure mode is building features in isolation without a unifying loop structure. It will create movement, inventory, combat, and crafting systems that all work independently but never form a cohesive game. The result is a playable sandbox with no progression, no session boundaries, no win/lose conditions, and no hooks for designers to tune pacing or difficulty. These patterns translate design intent ("the player explores, collects, crafts, then survives the night") into code architecture that enforces phase ordering, tracks session state, and exposes tuning surfaces to designers.

---

PATTERN: Core Loop Scaffolding

DESIGN INTENT: Designer describes the game as "explore, collect, craft, survive night" -- needs a code skeleton that enforces this cycle with extensible phases that run in order.

WRONG (Claude default):

// Systems built independently with no phase concept -- everything runs simultaneously.
// ExplorationManager, InventoryManager, CraftingManager, CombatManager all live in the scene
// and run their Update loops at the same time. There is no concept of "it is now the crafting
// phase" or "exploration has ended." The game is a flat sandbox.
public class GameManager : MonoBehaviour
{
    [SerializeField] private ExplorationManager _exploration;
    [SerializeField] private InventoryManager _inventory;
    [SerializeField] private CombatManager _combat;

    private void Start()
    {
        _exploration.Enable();
        _inventory.Enable();
        _combat.Enable(); // all systems active from frame 1
    }
}

RIGHT:

// GameLoopController manages phase transitions via IGamePhase interface.
// Each phase gets Enter/Tick/Exit. Phases are configured as SO assets.
// Only one phase is active at a time, enforcing the designer's intended cycle.
public interface IGamePhase
{
    /// <summary>Name shown in debug UI and logs.</summary>
    string PhaseName { get; }

    /// <summary>Called when this phase becomes active. Load assets, enable systems.</summary>
    Awaitable EnterAsync(CancellationToken ct);

    /// <summary>Called every frame while this phase is active.</summary>
    void Tick(float deltaTime);

    /// <summary>Called when transitioning away. Cleanup, disable systems.</summary>
    Awaitable ExitAsync(CancellationToken ct);
}

[CreateAssetMenu(menuName = "Game Loop/Phase Config")]
public class GamePhaseConfig : ScriptableObject
{
    [Tooltip("Display name for this phase")]
    public string phaseName;

    [Tooltip("Assembly-qualified type name of the IGamePhase implementation")]
    public string phaseTypeName;

    [Tooltip("Duration in seconds, 0 = phase decides when to end")]
    public float maxDuration;
}