Overview

WCGASResistanceSubsystem is a Game Instance Subsystem that serves as the central coordinator for the immunity and resistance system in the Wonderscape GAS Ally plugin. It automatically manages per-actor immunity GameplayEffects based on each actor's UWCGASResistanceComponent configuration, maintains isolated immunity states with unique FActiveGameplayEffectHandle per actor, handles dynamic immunity tag changes through GE refresh cycles (remove + reapply), integrates with the Diminishing Returns system to track effect applications and enforce DR-based immunity, and provides delegate bindings to ASC effect application events for automatic DR history recording.

Purpose

The Resistance Subsystem orchestrates all immunity and resistance behavior by providing:

• Automatic Registration: Components register/unregister via lifecycle hooks, with the subsystem managing their immunity GE state automatically
• Per-Actor Immunity Isolation: Each actor receives its own FActiveGameplayEffectHandle, ensuring immunity configuration affects only incoming effects to that specific actor
• Dynamic Immunity Refresh: When immunity tags change on a component, the subsystem compares against LastAppliedTags and only refreshes GE when tags actually differ
• Diminishing Returns Tracking: Binds to each ASC's OnGameplayEffectAppliedDelegateToSelf to record effect applications in the component's DR history
• DR Immunity Queries: Provides ShouldBlockEffectByDR() for external systems to check if an effect should be blocked based on accumulated DR stacks
• Configurable Immunity GE: Allows runtime configuration of the immunity GameplayEffect class via Project Settings or SetImmunityEffectClass()
• Cross-Actor ASC Resolution: Handles PlayerState/Pawn ASC ownership patterns through FindResistanceComponentForASC() lookup

How It Works

Initialization Flow

1. Subsystem Startup: When the GameInstance initializes, this subsystem automatically loads via UE's subsystem lifecycle
2. Load Immunity Effect Class: Retrieves the configured immunity GE class from Project Settings (if configured)
3. Prepare Registries: Initializes empty RegisteredComponents, ImmunityStates, and EffectAppliedDelegateHandles maps
4. Ready for Registration: Components that initialize after the subsystem will register automatically via their BeginPlay

Component Registration Flow