Skip to content

Recipe: Add an Ability

Goal: Create a new Gameplay Ability, configure its class defaults, implement its activation logic, and grant it to a character.

Prerequisites: A C++ base ability class and a character with an ASC. See C++ vs Blueprint for the recommended setup.

Steps

1. Create the Blueprint

  1. In Content Browser, right-click in your GAS/Abilities/ folder
  2. Select Blueprint Class
  3. Under "All Classes," search for your base ability class (e.g., MyGameplayAbility) -- or use GameplayAbility if you don't have a custom base
  4. Name it with the GA_ prefix: GA_Fireball

2. Set Class Defaults

Open the Blueprint and go to the Class Defaults panel:

Property Recommended Setting Notes
Ability Tags Ability.Combat.Ranged.Fireball Identifies this specific ability
Cancel Abilities with Tag (leave empty or set as needed) Abilities to cancel when this activates
Block Abilities with Tag (leave empty or set as needed) Abilities that can't activate while this is active
Activation Blocked Tags CrowdControl.Stun, State.Dead Tags on the owner that block activation
Activation Required Tags (usually empty) Tags the owner must have to activate
Instancing Policy InstancedPerActor Recommended default. See Instancing Policy.
Net Execution Policy LocalPredicted For player-activated abilities. See Net Execution Policies.
Cost GE Your cost effect (e.g., GE_Cost_Mana_30) Optional. See Cooldowns and Costs.
Cooldown GE Your cooldown effect (e.g., GE_Cooldown_3s) Optional

3. Wire ActivateAbility

In the Event Graph:

  1. The Event ActivateAbility node is your entry point
  2. Implement your ability logic:
    • Play montage (via PlayMontageAndWait task)
    • Wait for events (gameplay event, input, timer)
    • Apply effects to targets
  3. Always call EndAbility when the ability finishes
Event ActivateAbility
  → Commit Ability (checks cost + cooldown, deducts cost)
    → [Branch: success]
      → Play Montage And Wait
        → On Completed: End Ability
        → On Cancelled: End Ability
    → [Branch: fail]
      → End Ability

Always call EndAbility

An ability that never ends will block other abilities (if it has blocking tags) and leak resources. Every code path must reach EndAbility.

4. Grant to Character

In your character's initialization (BeginPlay or after ASC is ready):

void AMyCharacter::InitializeAbilities()
{
    if (HasAuthority() && AbilitySystemComponent)
    {
        for (TSubclassOf<UGameplayAbility>& Ability : DefaultAbilities)
        {
            AbilitySystemComponent->GiveAbility(
                FGameplayAbilitySpec(Ability, 1,
                    INDEX_NONE, this));
        }
    }
}

Call Give Ability on the ASC node, passing the ability class.

Use a UGameplayAbilitySet data asset to grant a collection of abilities, effects, and attribute sets together. See Ability Sets.

5. Test

  1. PIE
  2. Trigger the ability (via input binding or AbilitySystem.AbilityActivate console command)
  3. Verify it activates, plays feedback, and ends cleanly
  4. Check showdebug abilitysystem to confirm it appears in the ability list

Checklist

  • Blueprint created with GA_ prefix
  • Class Defaults configured (tags, instancing, net policy, cost, cooldown)
  • ActivateAbility wired with gameplay logic
  • EndAbility called on all exit paths
  • Ability granted to the character
  • Tested in PIE