Overview

The Faction System provides a flexible, Gameplay Tag-driven approach to defining relationships between actors in your game. It integrates seamlessly with the Gameplay Ability System, enabling faction-aware targeting for abilities, AI perception, and team-based mechanics.

The system consists of three interconnected classes:

Class Type Purpose
UWCGASFactionRelations Data Asset Designer-authorable asset defining relationships between faction pairs
IWCGASFactionAgent Interface Opt-in interface for actors that participate in the faction system
UWCGASFactionLib Blueprint Function Library Static helpers for querying faction relationships from anywhere 
flowchart TB
    subgraph DataLayer["Data Layer"]
        DA["UWCGASFactionRelations<br/>(Data Asset)"]
        Tags["Gameplay Tags<br/>Faction.Player<br/>Faction.Monsters<br/>etc."]
    end
    
    subgraph ActorLayer["Actor Layer"]
        Agent["IWCGASFactionAgent<br/>(Interface)"]
        ActorA["Actor A<br/>FactionTags: Player, Heroes"]
        ActorB["Actor B<br/>FactionTags: Monsters"]
    end
    
    subgraph QueryLayer["Query Layer"]
        Lib["UWCGASFactionLib<br/>(Blueprint Function Library)"]
    end
    
    subgraph ResultLayer["Result"]
        Result["EWCGASAttitude<br/>Friend / Neutral / Enemy"]
    end
    
    DA --> Tags
    ActorA --> Agent
    ActorB --> Agent
    Lib --> Agent
    Lib --> DA
    Lib --> Result
    
    style DataLayer fill:#4a90e2,stroke:#2171b5,color:#fff
    style ActorLayer fill:#41a161,stroke:#228b22,color:#fff
    style QueryLayer fill:#7b68ee,stroke:#6a5acd,color:#fff
    style ResultLayer fill:#b87700,stroke:#ff8c00,color:#fff

Core Types

EWCGASAttitude

The three-state attitude enum determines how actors perceive each other:

Value Description Use Case
Friend Full cooperation, no friendly fire Valid heal/buff target, allied AI
Neutral Non-hostile until provoked NPCs, wildlife, non-combatants
Enemy Valid combat target Hostile AI, ability damage targets

EWCGASFactionResolve

When actors belong to multiple factions, this determines which attitude wins:

Mode Behavior Best For
MostHostile Enemy wins if ANY pair is hostile Combat games ("attack if any reason to")
MostFriendly Friend wins if ANY pair is friendly Diplomacy games ("ally if any reason to")
Priority First faction (alphabetically) takes precedence Predictable results, primary faction matters most

Example with Multiple Factions:

ActorA factions: [Player, Heroes]
ActorB factions: [Monsters, Bandits]

Relations defined:
- Player vs Monsters: Enemy
- Player vs Bandits: Enemy  
- Heroes vs Monsters: Enemy
- Heroes vs Bandits: Neutral (truce)

Results:
- MostHostile:  → Enemy (any Enemy relation wins)
- MostFriendly: → Neutral (any non-Enemy relation wins)
- Priority:     → Enemy (Player vs Monsters checked first)

Step 1: Create Faction Relations Data Asset

UWCGASFactionRelations is the designer-authorable data asset that defines all faction relationships in your game.

Creating the Asset

  1. Right-click in Content Browser