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Overview

UMAS works independently of Unreal’s Gameplay Ability System, but it can also layer on top of GAS or feed into GAS attributes depending on your project needs. UMAS → GAS integration is optional, lightweight, and unintrusive. This page explains how to:
  • Use UMAS as your main attribute system while GAS handles abilities
  • Map UMAS attributes into GAS’s Attribute Sets
  • Trigger UMAS changes from GAS gameplay effects
  • Trigger GAS abilities based on UMAS attribute changes

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Integration Patterns

GAS handles:
  • Ability activation
  • Gameplay cues
  • Cooldowns
  • Costs
  • Combo systems
  • Skillshots
  • Replicated montage events
UMAS handles:
  • Stats
  • Scaling
  • Buffs/debuffs
  • Modifiers
  • Leveling
  • Effects
Why this works well:
  • UMAS has a more flexible data-driven stat system
  • GAS retains its best features without duplicating stats
  • No need to use GAS AttributeSet replication

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Pattern 2 — Hybrid Mode

Some attributes live in UMAS, some in GAS. Use this if:
  • You already have a GAS AttributeSet (e.g., for MMO abilities)
  • But want UMAS for item-based stats, survival stats, or leveling
UMAS→GAS bridge can update GAS attributes: 
UAbilitySystemComponent->SetNumericAttributeBase(HealthProperty, UMAS_Health);

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Pattern 3 — Full GAS Attribute Mirroring

If your game already heavily uses GAS, you can forward UMAS events:
  • OnAttributeChanged → ApplyGameplayEffect
  • OnLevelUp → ActivateAbility
  • UMAS effects → Convert to GE specs
This is the least common pattern but fully supported.

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Connecting UMAS to GAS

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1. Get GAS Component

UAbilitySystemComponent* ASC = FindComponentByClass<UAbilitySystemComponent>();

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2. Bind UMAS Attribute Changes

Attr->OnAttributeChangedNative.AddUObject(this, &ThisClass::SyncToGAS);

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3. Write a Sync Function

void AMyChar::SyncToGAS(FName Name, float NewVal)
{
    if (Name == "Health")
        ASC->SetNumericAttributeBase(UYourSet::GetHealthAttribute(), NewVal);
}

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Using UMAS Effects With GAS Cues

UMAS effects can trigger GAS cues:
  • Apply VFX
  • Apply SFX
  • Apply animations
  • Apply hit reactions
In Blueprint or C++: 
ASC->ExecuteGameplayCue(CueTag);
You can tag UMAS effects with GAS cue tags.

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Designer Notes

  • Use UMAS for “permanent” stats
  • Use GAS for instant gameplay moment reactions
  • Keep stat logic in one place (UMAS) to avoid fragmentation

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Developer Notes

  • UMAS is not dependent on GAS
  • GAS AttributeSets are optional
  • Syncing is unidirectional unless you choose otherwise
  • UMAS scaling + GAS abilities is a powerful combo