Core Concepts¶
This section breaks down each of the six pieces of GAS in depth. The Mental Model introduced them at a high level — here, you'll learn how each one actually works, what its API looks like, and where the gotchas hide.
The Six Pieces¶
Every GAS feature is built from some combination of these:
| Piece | Page | Role |
|---|---|---|
| Ability System Component | ASC | The hub — owns and orchestrates everything else |
| Gameplay Tags | Tags | The language — hierarchical labels that drive all GAS decisions |
| Attributes & Attribute Sets | Attributes | The stats — numeric values like Health, Mana, Armor |
| Gameplay Effects | Effects | The pipeline — the only way to modify attributes during gameplay |
| Gameplay Abilities | Abilities | The actions — discrete things a character can do |
| Gameplay Cues | Cues | The feedback — VFX and SFX, cosmetic only |
How They Depend on Each Other¶
These pieces aren't independent — they build on each other. Understanding the dependency chain helps you learn them in the right order.
graph TD
ASC[Ability System Component<br/><i>The Hub</i>]
GT[Gameplay Tags<br/><i>The Language</i>]
AS[Attributes & Attribute Sets<br/><i>The Stats</i>]
GE[Gameplay Effects<br/><i>The Pipeline</i>]
GA[Gameplay Abilities<br/><i>The Actions</i>]
GC[Gameplay Cues<br/><i>The Feedback</i>]
ASC --> GT
ASC --> AS
ASC --> GE
ASC --> GA
ASC --> GC
GE --> GT
GE --> AS
GE --> GC
GA --> GE
GA --> GT
GC --> GT
style ASC fill:#4051b5,color:#fff
style GT fill:#7c4dff,color:#fff
style AS fill:#00897b,color:#fff
style GE fill:#f57c00,color:#fff
style GA fill:#d32f2f,color:#fff
style GC fill:#8e24aa,color:#fff
Reading the diagram bottom-up:
- Effects depend on Attributes (they modify stats), Tags (they use tags for requirements and grants), and trigger Cues (for visual feedback).
- Abilities depend on Effects (they apply effects for costs, cooldowns, and results) and Tags (for activation rules).
- Cues depend on Tags (they're routed by GameplayCue.* tags) and are triggered by Effects.
- Everything flows through the ASC.
Suggested Reading Order¶
You can read these pages in any order, but this sequence minimizes "wait, what's that?" moments:
- Ability System Component — Start here. It's the hub that owns everything else, so understanding it first gives you context for the rest.
- Gameplay Tags — Tags are the language everything speaks. You'll see them referenced in every other page.
- Attributes and Attribute Sets — Your stats. Effects modify these, so learn what they are before learning how to change them.
- Gameplay Effects — The pipeline that modifies attributes, grants tags, and triggers cues.
- Gameplay Abilities — The actions your characters perform. They use effects, tags, and attributes.
- Gameplay Cues — Visual and audio feedback. Depends on effects and tags.
After this section, the Deep Dives go into exhaustive detail on Effects, Abilities, Cues, and Networking.