MCPInstall

ue-gameplay-abilities

Use when implementing or debugging the Gameplay Ability System in C++ — abilities, effects, attributes, cues and the AbilitySystemComponent. Also use when the user mentions 'GAS', 'UGameplayAbility', 'ActivateAbility', 'CommitAbility', 'UGameplayEffect', 'UAttributeSet', 'FGameplayAttributeData', 'AbilitySystemComponent', 'InitAbilityActorInfo', 'GiveAbility', 'TryActivateAbility', 'ability task', 'GameplayCue', 'cooldown', 'cost', 'buff', 'debuff', 'damage execution' or 'ASC on PlayerState'. For montage playback, see ue-animation-system; for replication modes and prediction, see ue-networking-replication.

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Install

Works with every agent the skills CLI supports.

npx skills add https://github.com/quodsoler/unreal-engine-skills --skill ue-gameplay-abilities
  1. 01

    Install

    Run the command in your project. The CLI asks which agents to install for.

  2. 02

    Describe the task

    Ask your agent for something this skill covers. It loads ue-gameplay-abilities automatically when relevant.

  3. 03

    Review the result

    The agent follows the SKILL.md steps, scripts and references bundled with the skill.

SKILL.md

The instructions your agent reads when the skill is triggered.

UE Gameplay Ability System

Target engine: UE 5.8. APIs below are verified against the 5.8 headers; older forms are listed under "Deprecated — do not use".

GAS ships as the GameplayAbilities plugin (Engine/Plugins/Runtime/GameplayAbilities), which is production-ready, not Experimental. Enable it in the .uproject, then add "GameplayAbilities", "GameplayTags" and "GameplayTasks" to PublicDependencyModuleNames in your module's Build.cs. This skill covers UAbilitySystemComponent, UGameplayAbility, UGameplayEffect, UAttributeSet, UAbilityTask and Gameplay Cues.

Context

Read .agents/ue-project-context.md if it exists (module names, conventions, enabled plugins, GAS/networking setup). Do not stop if it is missing.

Identify the area from the request and the codebase. Ask only when two plausible readings would produce different code.

Request is about…Go to
Where the ASC lives, init order, respawn, replication modeASC Ownership and Initialization
Writing an ability, activation, cost, cooldown, policiesGameplay Abilities
Waiting on montages, events, targeting, timers, tag queriesAbility Tasks
Damage, buffs, stacking, executions, immunity, GE componentsGameplay Effects
Health/mana floats, clamping, attribute replicationAttribute Sets
Tags that block, grant or cancel abilities; loose tagsTags in GAS
Particles, sounds, hit impacts, cue notify classesGameplay Cues
Cue scan paths, global curve tables, project configProject Settings

GAS Architecture

PillarClassHeaderPurpose
ComponentUAbilitySystemComponentAbilitySystemComponent.hOwns abilities, effects, attributes, tags
AbilitiesUGameplayAbilityAbilities/GameplayAbility.hWhat happens when activated
EffectsUGameplayEffectGameplayEffect.hData-driven attribute mutation
AttributesUAttributeSetAttributeSet.hReplicated FGameplayAttributeData stats
TasksUAbilityTaskAbilities/Tasks/AbilityTask.hLatent steps inside an ability

Gameplay tags thread through all of them as requirements, grants and blockers.

ASC Ownership and Initialization

OwnerWhenNotes
APlayerStateNetworked player charactersASC survives pawn death; use Mixed replication
APawn / ACharacterAI, single-playerSimplest; use Minimal for AI, Full if a pawn-owned ASC needs full data on all clients

Every actor that owns or exposes an ASC implements IAbilitySystemInterface:

// MyCharacter.h
#pragma once

#include "GameFramework/Character.h"
#include "AbilitySystemInterface.h"
#include "MyCharacter.generated.h"

class UAbilitySystemComponent;

UCLASS()
class MYGAME_API AMyCharacter : public ACharacter, public IAbilitySystemInterface
{
    GENERATED_BODY()

public:
    AMyCharacter();

    virtual UAbilitySystemComponent* GetAbilitySystemComponent() const override;

protected:
    UPROPERTY(VisibleAnywhere, BlueprintReadOnly, Category = "GAS")
    TObjectPtr<UAbilitySystemComponent> AbilitySystemComponent;
};
// MyCharacter.cpp
#include "MyCharacter.h"
#include "AbilitySystemComponent.h"

AMyCharacter::AMyCharacter()
{
    AbilitySystemComponent = CreateDefaultSubobject<UAbilitySystemComponent>(TEXT("AbilitySystemComponent"));
    AbilitySystemComponent->SetIsReplicated(true);
    AbilitySystemComponent->SetReplicationMode(EGameplayEffectReplicationMode::Mixed);
}

UAbilitySystemComponent* AMyCharacter::GetAbilitySystemComponent() const
{
    return AbilitySystemComponent;
}

InitAbilityActorInfo(OwnerActor, AvatarActor) must run on both server and client. For a pawn-owned ASC that is BeginPlay with (this, this). For a PlayerState-owned ASC it is PossessedBy on the server and OnRep_PlayerState on the client, with (PlayerState, Character). Full dual-path code, respawn handling and the AI variant are in gas-setup-patterns.md.

EGameplayEffectReplicationModeEffect on simulated proxies
MinimalNo GE replication; minimal tag/cue data only. AI and non-player actors
MixedFull GEs to the owning connection, minimal to everyone else. Player characters
FullEvery GE replicates to every client

Mixed sends full GE data to the connection that owns the ASC's owner actor (GameplayEffect.cpp:5240), so it works for a PlayerState-owned ASC and for a pawn-owned ASC once a PlayerController possesses the pawn. Choosing Full over Mixed is a bandwidth decision, not a correctness one. Minimal does not work for player-owned ASCs (AbilitySystemComponent.h:83). See ue-networking-replication for what each mode costs on the wire.

Gameplay Abilities

// MyFireballAbility.h
#pragma once

#include "Abilities/GameplayAbility.h"
#include "MyFireballAbility.generated.h"

class UGameplayEffect;

UCLASS()
class MYGAME_API UMyFireballAbility : public UGameplayAbility
{
    GENERATED_BODY()

public:
    UMyFireballAbility();

    virtual bool CanActivateAbility(const FGameplayAbilitySpecHandle Handle,
        const FGameplayAbilityActorInfo* ActorInfo,
        const FGameplayTagContainer* SourceTags = nullptr,
        const FGameplayTagContainer* TargetTags = nullptr,
        OUT FGameplayTagContainer* OptionalRelevantTags = nullptr) const override;

    virtual void ActivateAbility(const FGameplayAbilitySpecHandle Handle,
        const FGameplayAbilityActorInfo* ActorInfo,
        const FGameplayAbilityActivationInfo ActivationInfo,
        const FGameplayEventData* TriggerEventData) override;

    virtual void EndAbility(const FGameplayAbilitySpecHandle Handle,
        const FGameplayAbilityActorInfo* ActorInfo,
        const FGameplayAbilityActivationInfo ActivationInfo,
        bool bReplicateEndAbility, bool bWasCancelled) override;

    virtual void CancelAbility(const FGameplayAbilitySpecHandle Handle,
        const FGameplayAbilityActorInfo* ActorInfo,
        const FGameplayAbilityActivationInfo ActivationInfo,
        bool bReplicateCancelAbility) override;

protected:
    UPROPERTY(EditDefaultsOnly, Category = "GAS")
    TSubclassOf<UGameplayEffect> DamageEffect;
};

Constructor sets the policies and the ability's own tags:

// MyFireballAbility.cpp
#include "MyFireballAbility.h"
#include "AbilitySystemBlueprintLibrary.h"
#include "AbilitySystemComponent.h"

UMyFireballAbility::UMyFireballAbility()
{
    InstancingPolicy = EGameplayAbilityInstancingPolicy::InstancedPerActor;
    NetExecutionPolicy = EGameplayAbilityNetExecutionPolicy::LocalPredicted;
    NetSecurityPolicy = EGameplayAbilityNetSecurityPolicy::ClientOrServer;

    FGameplayTagContainer Tags;
    Tags.AddTag(FGameplayTag::RequestGameplayTag(TEXT("Ability.Skill.Fireball")));
    SetAssetTags(Tags);

    ActivationOwnedTags.AddTag(FGameplayTag::RequestGameplayTag(TEXT("Ability.Active.Casting")));
    ActivationBlockedTags.AddTag(FGameplayTag::RequestGameplayTag(TEXT("State.Stunned")));
    CancelAbilitiesWithTag.AddTag(FGameplayTag::RequestGameplayTag(TEXT("Ability.Active.Melee")));
}

SetAssetTags is constructor-only; read them back with GetAssetTags().

EnumValuesUse
EGameplayAbilityInstancingPolicyInstancedPerActor, InstancedPerExecutionInstancedPerActor is the default choice; per-execution when several copies may run at once
EGameplayAbilityNetExecutionPolicyLocalPredicted, LocalOnly, ServerInitiated, ServerOnlyLocalPredicted for responsive player abilities
EGameplayAbilityNetSecurityPolicyClientOrServer, ServerOnlyExecution, ServerOnlyTermination, ServerOnlyRejects client requests the server should own
void UMyFireballAbility::ActivateAbility(const FGameplayAbilitySpecHandle Handle,
    const FGameplayAbilityActorInfo* ActorInfo,
    const FGameplayAbilityActivationInfo ActivationInfo,
    const FGameplayEventData* TriggerEventData)
{
    Super::ActivateAbility(Handle, ActorInfo, ActivationInfo, TriggerEventData);

    // CommitAbility applies cost and cooldown; it fails if either cannot be paid.
    if (!CommitAbility(Handle, ActorInfo, ActivationInfo))
    {
        EndAbility(Handle, ActorInfo, ActivationInfo, true, true);
        return;
    }

    const FGameplayEffectSpecHandle Spec =
        MakeOutgoingGameplayEffectSpec(DamageEffect, GetAbilityLevel());
    const FGameplayAbilityTargetDataHandle TargetData =
        UAbilitySystemBlueprintLibrary::AbilityTargetDataFromActor(ActorInfo->AvatarActor.Get());

    ApplyGameplayEffectSpecToTarget(Handle, ActorInfo, ActivationInfo, Spec, TargetData);
    EndAbility(Handle, ActorInfo, ActivationInfo, true, false);
}

Split the commit when the two halves must happen at different times: CommitAbilityCost(Handle, ActorInfo, ActivationInfo) and CommitAbilityCooldown(Handle, ActorInfo, ActivationInfo, ForceCooldown) — note the cooldown overload takes the extra const bool ForceCooldown.

Inside an instanced ability, GetAbilitySystemComponentFromActorInfo_Ensured() returns the ASC and logs an ensure instead of crashing when actor info is not set up.

Granting and activating, from the server:

const FGameplayAbilitySpecHandle Handle =
    ASC->GiveAbility(FGameplayAbilitySpec(UMyFireballAbility::StaticClass(), 1));

ASC->TryActivateAbility(Handle);
ASC->TryActivateAbilityByClass(UMyFireballAbility::StaticClass());
ASC->TryActivateAbilitiesByTag(
    FGameplayTagContainer(FGameplayTag::RequestGameplayTag(TEXT("Ability.Skill.Fireball"))));
ASC->ClearAbility(Handle);

Ability Tasks

Ability tasks make an ability span frames. The pattern is always: static factory → bind delegates → ReadyForActivation() (inherited from UGameplayTask). Task delegates are dynamic, so each handler needs UFUNCTION():

// In the ability's header:
UFUNCTION()
void HandleMontageCompleted();

UFUNCTION()
void HandleMontageInterrupted();
#include "Abilities/Tasks/AbilityTask_PlayMontageAndWait.h"

UAbilityTask_PlayMontageAndWait* Task =
    UAbilityTask_PlayMontageAndWait::CreatePlayMontageAndWaitProxy(
        this, NAME_None, AttackMontage, 1.f);
Task->OnCompleted.AddDynamic(this, &UMyFireballAbility::HandleMontageCompleted);
Task->OnInterrupted.AddDynamic(this, &UMyFireballAbility::HandleMontageInterrupted);
Task->ReadyForActivation();
TaskWaits for
UAbilityTask_PlayMontageAndWaitAn UAnimMontage to finish, blend out, interrupt or cancel
UAbilityTask_PlayAnimAndWaitA raw UAnimSequence played into a slot, for linked anim layers
UAbilityTask_WaitGameplayEventA gameplay event tag sent to the ASC (anim notify, hit registration)
UAbilityTask_WaitDelayA fixed number of seconds
UAbilityTask_WaitTargetDataAn AGameplayAbilityTargetActor to confirm targets
UAbilityTask_WaitAttributeChange / ...ChangeThresholdAn attribute to change or cross a comparison
UAbilityTask_WaitGameplayTagQueryAn FGameplayTagQuery over the target's tags to become true or false
UAbilityTask_WaitGameplayTagCountChangedThe count of one tag on the ASC to change
UAbilityTask_WaitGameplayEffectApplied_Self / _TargetA GE matching tag requirements (or an FGameplayTagQuery via the _Query factories)

Full factory signatures, delegate names, the custom-task template and the task pitfalls are in ability-task-reference.md.

Gameplay Effects

EGameplayEffectDurationTypeBehaviour
InstantExecutes once against the base value; fires PostGameplayEffectExecute
HasDurationAggregates onto the current value for DurationMagnitude seconds
InfiniteAggregates until removed explicitly
const FGameplayEffectContextHandle Ctx = ASC->MakeEffectContext();
const FGameplayEffectSpecHandle Spec =
    ASC->MakeOutgoingSpec(UMyDamageEffect::StaticClass(), Level, Ctx);

Spec.Data->SetSetByCallerMagnitude(
    FGameplayTag::RequestGameplayTag(TEXT("SetByCaller.Damage")), 75.f);

ASC->ApplyGameplayEffectSpecToSelf(*Spec.Data.Get());
ASC->ApplyGameplayEffectSpecToTarget(*Spec.Data.Get(), TargetASC);

ASC->RemoveActiveGameplayEffect(ActiveHandle);
ASC->RemoveActiveGameplayEffectBySourceEffect(UMyDamageEffect::StaticClass(), nullptr);

Modifier ops live in EGameplayModOp (a namespaced enum, so values are TEnumAsByte<EGameplayModOp::Type>). The aggregation equation is ((BaseValue + AddBase) * MultiplyAdditive / DivideAdditive * MultiplyCompound) + AddFinal.

ValueMeaning
AddBaseAdded to the base before anything else
MultiplyAdditiveMultipliers summed, then multiplied against the running result
DivideAdditiveDivisors summed, then divided against the running result
MultiplyCompoundMultiplied into the running result, compounding with other compounds
AddFinalAdded after all multiplication
OverrideReplaces the computed value

Behaviour that used to be monolithic properties on UGameplayEffect now lives in UGameplayEffectComponent subclasses under GameplayEffectComponents/. Stacking, magnitude calculations, UGameplayEffectExecutionCalculation, periodic effects, immunity, queries, lifecycle delegates and the full component list are in gameplay-effect-reference.md.

Attribute Sets

// MyHealthSet.h
#pragma once

#include "AttributeSet.h"
#include "AbilitySystemComponent.h"
#include "MyHealthSet.generated.h"

UCLASS()
class MYGAME_API UMyHealthSet : public UAttributeSet
{
    GENERATED_BODY()

public:
    UMyHealthSet();

    virtual void PreAttributeChange(const FGameplayAttribute& Attribute, float& NewValue) override;
    virtual void PostGameplayEffectExecute(const struct FGameplayEffectModCallbackData& Data) override;
    virtual void GetLifetimeReplicatedProps(TArray<FLifetimeProperty>& OutLifetimeProps) const override;

    UPROPERTY(BlueprintReadOnly, ReplicatedUsing = OnRep_Health, Category = "Health")
    FGameplayAttributeData Health;
    ATTRIBUTE_ACCESSORS_BASIC(UMyHealthSet, Health)

    UPROPERTY(BlueprintReadOnly, ReplicatedUsing = OnRep_MaxHealth, Category = "Health")
    FGameplayAttributeData MaxHealth;
    ATTRIBUTE_ACCESSORS_BASIC(UMyHealthSet, MaxHealth)

protected:
    UFUNCTION()
    void OnRep_Health(const FGameplayAttributeData& OldHealth);

    UFUNCTION()
    void OnRep_MaxHealth(const FGameplayAttributeData& OldMaxHealth);
};

ATTRIBUTE_ACCESSORS_BASIC generates GetHealthAttribute(), GetHealth(), SetHealth() and InitHealth(). Projects that want extra accessors define their own macro chaining GAMEPLAYATTRIBUTE_PROPERTY_GETTER, GAMEPLAYATTRIBUTE_VALUE_GETTER, GAMEPLAYATTRIBUTE_VALUE_SETTER and GAMEPLAYATTRIBUTE_VALUE_INITTER.

Each OnRep_ body is one GAMEPLAYATTRIBUTE_REPNOTIFY(UMyHealthSet, Health, OldHealth) call, and every attribute needs a DOREPLIFETIME_CONDITION_NOTIFY(UMyHealthSet, Health, COND_None, REPNOTIFY_Always) line. The full .cpp with clamping is in gas-setup-patterns.md.

HookFiresUse for
PreAttributeChangeEvery current-value recomputeClamping the current value only
PreAttributeBaseChangeBefore a base-value write (const)Clamping the base value
PostGameplayEffectExecuteAfter an instant GE, or one period of a periodic GE, writes the base valueDeath, hit reactions, game events
PostAttributeChangeAfter a current value changedReacting to derived state

Registering and reading:

// Constructor of the ASC owner — the ASC finds subobject attribute sets automatically:
HealthSet = CreateDefaultSubobject<UMyHealthSet>(TEXT("HealthSet"));

// Runtime, authority only:
UMyHealthSet* NewSet = NewObject<UMyHealthSet>(this);
ASC->AddSpawnedAttribute(NewSet);

const float CurrentHealth = ASC->GetNumericAttribute(UMyHealthSet::GetHealthAttribute());

One ASC can host several UAttributeSet subclasses, but only one instance per class.

Tags in GAS

Tag definition (native tag macros, .ini tag sources), container matching and FGameplayTagQuery semantics belong to ue-gameplay-tags-messaging. What is GAS-specific:

// On the ability CDO (constructor): tags granted while the ability runs, and the gates.
ActivationOwnedTags.AddTag(CastingTag);
ActivationRequiredTags.AddTag(WeaponEquippedTag);
ActivationBlockedTags.AddTag(StunnedTag);
BlockAbilitiesWithTag.AddTag(MeleeTag);
CancelAbilitiesWithTag.AddTag(ChannelTag);

// On the ASC: query and react.
ASC->HasMatchingGameplayTag(StunnedTag);
const FGameplayTagContainer& Owned = ASC->GetOwnedGameplayTags();
ASC->RegisterGameplayTagEvent(StunnedTag, EGameplayTagEventType::NewOrRemoved)
    .AddUObject(this, &AMyCharacter::HandleStunnedTagChanged);

The callback is declared as void HandleStunnedTagChanged(const FGameplayTag Tag, int32 NewCount); and needs no UFUNCTION() — tag events are plain multicast delegates.

Loose tags are set directly instead of through a GE. The third argument chooses how the tag replicates:

ASC->AddLooseGameplayTag(StunnedTag);                                              // local only
ASC->AddLooseGameplayTag(BuffedTag, 1, EGameplayTagReplicationState::TagOnly);     // tag to all
ASC->AddLooseGameplayTag(BuffedTag, 1, EGameplayTagReplicationState::CountToOwner);// + count to owner
ASC->RemoveLooseGameplayTag(BuffedTag, 1, EGameplayTagReplicationState::TagOnly);
ASC->SetLooseGameplayTagCount(BuffedTag, 3, EGameplayTagReplicationState::TagAndCountToAll);

EGameplayTagReplicationState values: None, SimulatedTagOnly, TagOnly, CountToOwner, TagAndCountToAll. Anything other than None must be added on the server.

Gameplay Cues

Cues are cosmetic only. Tag prefix GameplayCue.; a GE triggers them through its GameplayCues array, or code fires them directly:

ASC->ExecuteGameplayCue(HitCueTag, ASC->MakeEffectContext());   // one-shot
ASC->AddGameplayCue(BuffCueTag);                                // persistent
ASC->RemoveGameplayCue(BuffCueTag);
const bool bActive = ASC->IsGameplayCueActive(BuffCueTag);
ClassBaseOverrideUse
UGameplayCueNotify_StaticUObjectOnExecute_ImplementationBurst cue with no spawned actor
UGameplayCueNotify_BurstUGameplayCueNotify_Staticdata-driven burst effectsOne-shot particles/sounds, no code
UGameplayCueNotify_HitImpactUGameplayCueNotify_Staticdata-driven impact effectsSurface-typed impacts
AGameplayCueNotify_ActorAActorOnActive_/WhileActive_/OnRemove_ImplementationPersistent cue needing an actor
AGameplayCueNotify_BurstLatentAGameplayCueNotify_Actordata-driven burst effectsBurst that must spawn an actor
AGameplayCueNotify_LoopingAGameplayCueNotify_Actordata-driven looping effectsLooping auras and channels
// MyHitCue.h
#pragma once

#include "GameplayCueNotify_Static.h"
#include "MyHitCue.generated.h"

UCLASS()
class MYGAME_API UMyHitCue : public UGameplayCueNotify_Static
{
    GENERATED_BODY()

public:
    virtual bool OnExecute_Implementation(AActor* MyTarget,
        const FGameplayCueParameters& Parameters) const override;
};

UGameplayCueManager discovers cue assets under the scan paths configured in project settings.

Project Settings

GAS configuration is a UDeveloperSettings class: UGameplayAbilitiesDeveloperSettings (Project Settings → Gameplay Abilities). Read it with GetDefault<UGameplayAbilitiesDeveloperSettings>(). Notable fields: GameplayCueNotifyPaths, ReplicateActivationOwnedTags, bAllowGameplayModEvaluationChannels, plus the global curve/attribute tables. Runtime helpers stay on UAbilitySystemGlobals (GetGameplayCueNotifyPaths(), AddGameplayCueNotifyPath(), GetAttributeSetInitter()).

Deprecated — do not use

Do not emitUse in 5.8Source
AGameplayCueNotify_StaticUGameplayCueNotify_Static (a UObject)Class never existed; GameplayCueNotify_Static.h:19
EGameplayModOp::MultiplicativeEGameplayModOp::MultiplyAdditive (legacy alias is spelled Multiplicitive)GameplayEffectTypes.h:112-148
EGameplayModOp::Additive / DivisionAddBase / DivideAdditiveHidden back-compat aliases, GameplayEffectTypes.h:141-143
EGameplayAbilityInstancingPolicy::NonInstancedInstancedPerActorUE_DEPRECATED_FORGAME(5.5) in Abilities/GameplayAbilityTypes.h:46
UGameplayAbility::AbilityTagsGetAssetTags() / SetAssetTags()UE_DEPRECATED_FORGAME(5.5) in Abilities/GameplayAbility.h:474
GetAbilitySystemComponentFromActorInfo_Checked()GetAbilitySystemComponentFromActorInfo_Ensured()UE_DEPRECATED(5.5) in Abilities/GameplayAbility.h:168
NetUpdateFrequency assignment on an actorSetNetUpdateFrequency(100.f)UE_DEPRECATED(5.5) in GameFramework/Actor.h:903
UGameplayEffect::StackingType (public read)GetStackingType()UE_DEPRECATED(5.7) in GameplayEffect.h:2407
UGameplayEffect::GrantedApplicationImmunityTagsUImmunityGameplayEffectComponentUE_DEPRECATED(5.3) in GameplayEffect.h:2379
AddReplicatedLooseGameplayTagAddLooseGameplayTag(Tag, Count, EGameplayTagReplicationState::CountToOwner) (the deprecation message's replacement; TagOnly if no client needs the count)Function removed (no declaration in 5.8); the backing ReplicatedLooseTags member is UE_DEPRECATED(5.7) at AbilitySystemComponent.h:1941
FGameplayAbilitySpec::DynamicAbilityTagsGetDynamicSpecSourceTags()UE_DEPRECATED(5.5) in GameplayAbilitySpec.h:242
UAbilitySystemBlueprintLibrary::MakeSpecHandleMakeSpecHandleByClassUE_DEPRECATED(5.5) in AbilitySystemBlueprintLibrary.h:249
UAbilitySystemGlobals config membersGetDefault<UGameplayAbilitiesDeveloperSettings>()UE_DEPRECATED(5.5) throughout AbilitySystemGlobals.h
FGameplayEffectSpec::GetModifierMagnitude(ModifierIdx, bFactorInStackCount)GetModifierMagnitude(int32 ModifierIdx)UE_DEPRECATED(5.6) in GameplayEffect.h:1153
FActiveGameplayEffectHandle(int32), ResetGlobalHandleMap(), RemoveFromGlobalMap()FActiveGameplayEffectHandle::GenerateNewHandle() or GetInstantExecutedHandle(); the global map is goneUE_DEPRECATED(5.8) in ActiveGameplayEffectHandle.h:30,66,69

Common Mistakes

Implementing IAbilitySystemInterface only on the pawn: when the ASC lives on the PlayerState, the PlayerState must implement the interface too, otherwise UAbilitySystemBlueprintLibrary::GetAbilitySystemComponent fails on the owner.

Calling InitAbilityActorInfo only on the server: clients need it as well. Server path is PossessedBy, client path is OnRep_PlayerState. Without the client call, attribute change delegates never fire on the owning client.

Applying GEs before init: granting abilities or applying effects before InitAbilityActorInfo runs leaves the ASC without actor info and the attribute sets unregistered.

Clamping in the wrong hook: PreAttributeChange fires on every aggregator recompute, so it may only clamp NewValue. Death, hit reactions and gameplay events belong in PostGameplayEffectExecute, which only runs for executions (instant GEs and periodic ticks).

Forgetting CommitAbility: the ability runs, but no cost is paid and no cooldown starts.

Assuming loose tags replicate: AddLooseGameplayTag(Tag) defaults to EGameplayTagReplicationState::None. Pass TagOnly or CountToOwner from the server, or grant the tag through a GE.

Stacks silently capped: applications beyond GetStackLimitCount() are rejected without an error. Check GetCurrentStackCount(Handle) before assuming a stack landed.

Startup effects in BeginPlay without an authority check: late joiners re-apply them. Gate every GiveAbility and startup GE behind HasAuthority().

AI with no PlayerState: put the ASC on the AI character, call InitAbilityActorInfo(this, this) and set Minimal replication.

Related Skills

  • ue-gameplay-tags-messaging — tag definition (native tag macros, ini tag sources), containers, FGameplayTagQuery and gameplay messaging
  • ue-networking-replication — DOREPLIFETIME variants, RPCs, prediction keys, push model
  • ue-animation-system — montage assets, notifies and slots that the montage ability tasks drive
  • ue-character-movement — movement modes that root-motion ability tasks manipulate
  • ue-cpp-foundations — UPROPERTY/UFUNCTION specifiers, delegates, TSubclassOf, subsystems
  • ue-data-assets-tables — UCurveTable and UDataTable assets behind attribute initialisation and FScalableFloat
  • ue-state-trees — running abilities from State Tree tasks
  • ue-actor-component-architecture — component creation, subobject registration, replication of subobjects
  • ue-gameplay-framework — PlayerState and Pawn lifecycle, and damage without GAS (TakeDamage, UDamageType)
  • ue-input-system — Enhanced Input actions bound to ability input ids
  • ue-game-features — granting abilities and attribute sets from a game feature plugin
  • ue-niagara-effects — Niagara systems, user parameters, data interfaces and data channels
  • ue-ui-umg-slate — UMG widgets, Slate, Common UI and MVVM

FAQ

What does the ue-gameplay-abilities skill do?

Use when implementing or debugging the Gameplay Ability System in C++ — abilities, effects, attributes, cues and the AbilitySystemComponent. Also use when the user mentions 'GAS', 'UGameplayAbility', 'ActivateAbility', 'CommitAbility', 'UGameplayEffect', 'UAttributeSet', 'FGameplayAttributeData', 'AbilitySystemComponent', 'InitAbilityActorInfo', 'GiveAbility', 'TryActivateAbility', 'ability task', 'GameplayCue', 'cooldown', 'cost', 'buff', 'debuff', 'damage execution' or 'ASC on PlayerState'. For montage playback, see ue-animation-system; for replication modes and prediction, see ue-networking-replication.

How do I install ue-gameplay-abilities?

Run npx skills add https://github.com/quodsoler/unreal-engine-skills --skill ue-gameplay-abilities in your project. The skills CLI detects the agents you use and copies the skill into the right folder. For Claude Code you can also place the skill folder at ~/.claude/skills/ue-gameplay-abilities/ (personal) or .claude/skills/ue-gameplay-abilities/ (project).

Which AI agents can use ue-gameplay-abilities?

Any agent that supports the open Agent Skills format (a folder with a SKILL.md file), including Claude Code, Codex, Cursor, GitHub Copilot, Gemini CLI, Windsurf, Cline, OpenCode and more.

Is ue-gameplay-abilities safe to install?

No partner security audit is available yet. Skills can run commands and scripts, so read the SKILL.md and any bundled files before installing.

Who maintains ue-gameplay-abilities?

It is published by quodsoler in quodsoler/unreal-engine-skills. It has 1,157 recorded installs.

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Use when extending the Unreal Editor from C++ with detail customizations, editor utility widgets, menus, editor modes, asset definitions or editor subsystems. Also use when the user mentions 'IDetailCustomization', 'IPropertyTypeCustomization', 'CustomizeDetails', 'RegisterCustomClassLayout', 'IDetailLayoutBuilder', 'AddCustomRow', 'IPropertyHandle', 'UToolMenus', 'ExtendMenu', 'FToolMenuEntry', 'UEditorUtilityWidget', 'Blutility', 'UAssetActionUtility', 'UEditorSubsystem', 'UEdMode', 'UAssetDefinition', 'UFactory', 'FScopedTransaction', or 'editor module'. For Slate fundamentals, see ue-ui-umg-slate; for Build.cs wiring, see ue-module-build-system.

Frontend & Design1.3K installs

ue-project-context

quodsoler/unreal-engine-skills

Use when creating, refreshing or repairing .agents/ue-project-context.md, the project document every other UE skill reads first. Also use when the user says 'project context', 'set up context', 'UE context', 'scan my project', 'onboard the agent to my project', 'update project context', 'configure project', 'what engine version is this project on', 'which plugins do we have enabled', or complains that UE advice keeps coming out generic. For Build.cs and Target.cs mechanics, see ue-module-build-system; for naming and API-macro conventions, see ue-cpp-foundations; for GAS specifics, see ue-gameplay-abilities.

Backend & APIs1.3K installs

ue-testing-debugging

quodsoler/unreal-engine-skills

Use when writing or running Unreal Engine tests, adding logging, or profiling a build. Also use when the user mentions 'UELOG', 'log category', 'DEFINELOGCATEGORY', 'UELOGFMT', 'verbosity', 'check', 'ensure', 'ensureMsgf', 'verify', 'IMPLEMENTSIMPLEAUTOMATIONTEST', 'automation test', 'TESTCLASS', 'CQTest', 'AFunctionalTest', 'latent command', 'Unreal Insights', 'TRACECPUPROFILEREVENTSCOPE', 'TRACEBOOKMARK', 'stat unit', 'SCOPECYCLECOUNTER', 'memreport', 'DrawDebugLine', 'UEVLOG', 'gameplay debugger', 'ShowDebug', 'console command', 'CVar', or 'why is my frame time bad'. For module and target wiring, see ue-module-build-system; for editor tooling, see ue-editor-tools.

Testing & QA1.3K installs

ue-module-build-system

quodsoler/unreal-engine-skills

Use when writing or fixing Build.cs, Target.cs, .uproject or .uplugin files, creating a module or plugin, or resolving an Unreal build error. Also use when the user mentions 'unresolved external symbol', 'LNK2019', 'cannot open include file', 'C1083', 'MODULENAMEAPI', 'PublicDependencyModuleNames', 'IWYU', 'PCHUsage', 'IMPLEMENTMODULE', 'IMPLEMENTPRIMARYGAMEMODULE', 'LoadingPhase', 'circular dependency', 'Missing precompiled manifest', 'EngineAssociation', 'IncludeOrderVersion', 'Live Coding'. For UCLASS/UPROPERTY rules see ue-cpp-foundations; for editor modules see ue-editor-tools; for Game Feature plugins see ue-game-features.

Media & Creative1.3K installs

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setup-matt-pocock-skills

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frontend-design

anthropics/skills

Guidance for distinctive, intentional visual design when building new UI or reshaping an existing one. Helps with aesthetic direction, typography, and making choices that don't read as templated defaults.

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hyperframes-animation

heygen-com/hyperframes

All animation knowledge for HyperFrames — atomic motion rules, multi-phase scene blueprints, scene transitions, broader motion-design techniques, AND the seven runtime adapters (GSAP default, plus Lottie, Three.js, Anime.js, CSS keyframes, Web Animations API, TypeGPU). Use for any motion or animation task: pick 2-4 rules and compose, or load a blueprint, or look up runtime-specific API (e.g. GSAP eases / Lottie player / Three.js mixer). Also covers auditing an existing composition's choreography (animation map) and 24 named text-animation effects. HyperFrames-native: single paused timeline, seek-safe, deterministic.

prototype

mattpocock/skills

Build a throwaway prototype to answer a design question. Use when the user wants to sanity-check whether a state model or logic feels right, or explore what a UI should look like.

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hyperframes-core

heygen-com/hyperframes

The HyperFrames composition contract — build one renderable project. Use for composition structure, the data- timing attributes, class="clip", tracks, sub-compositions, variables, framework-owned media playback, deterministic-render rules, and validation. Read before writing composition HTML.

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vercel-react-best-practices

vercel-labs/agent-skills

React and Next.js performance optimization guidelines from Vercel Engineering. This skill should be used when writing, reviewing, or refactoring React/Next.js code to ensure optimal performance patterns. Triggers on tasks involving React components, Next.js pages, data fetching, bundle optimization, or performance improvements.

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