Overview

WCGASEventSubsystem is a Game Instance Subsystem that provides centralized event broadcasting for Gameplay Ability System events. It bridges the gap between GAS's C++-centric architecture and Blueprint-focused designers, allowing them to respond to attribute changes, threshold crossings, and zero events without writing C++ code or creating custom Gameplay Abilities.

Purpose

The Event Subsystem empowers Blueprint-only designers by providing:

• Global Event Broadcasting: Fires delegates when any attribute reaches zero, crosses thresholds, or changes values across all ASCs
• Targeted Attribute Monitoring: Allows binding to specific attribute changes on specific ASCs for efficient production use
• Blueprint-Accessible Delegates: Exposes all events to Blueprint for easy implementation of UI updates, death logic, and warnings
• Automatic Memory Management: Uses weak object pointers and automatic cleanup to prevent memory leaks when actors are destroyed
• Multi-Listener Support: Enables multiple systems to respond to the same event without coupling them together

How It Works

Initialization Flow

1. Subsystem Startup: When the GameInstance initializes, this subsystem automatically loads via Unreal's subsystem framework
2. Delegate Setup: Initializes internal data structures for binding management in Initialize()
3. Ready for Binding: Blueprint and C++ code can now bind to global delegates or create targeted bindings
4. Event Integration: WCGASAttributePool calls broadcast functions during attribute modifications

Broadcasting Flow

When attributes are modified:

1. WCGASAttributePool detects attribute changes in PostGameplayEffectExecute() or PreAttributeChange()