Building a Modular Ability System in Unreal Engine
Introduction
As part of my ongoing technical design work, I’ve been building a modular ability system in Unreal Engine, using a combination of C++ and Blueprints to create a scalable, data-driven framework. This project is both a practical tool for gameplay prototyping and an exercise in treating personal development with the same structure and planning I’d apply in a studio environment.
In this breakdown, I’ll walk through the process from conceptualization and system design to implementation and iteration.
Why Build a Modular Ability System?
Whether they’re simple attacks, healing spells, dashes, or buffs, abilities are fundamental to countless game genres. But as a technical designer, I’m less interested in just building individual abilities and more focused on creating a system that empowers designers to define abilities easily, modify parameters, and add new types without changing core code.
My design goals for this system:
• Data-driven: New abilities should be created via data assets, not hardcoded logic.
• Modular and scalable: Ability execution logic should be extensible without refactoring.
• Designer-friendly: Blueprint-accessible and readable, even for non-programmers.
• Clean, maintainable architecture: Future features like combos or upgrades should integrate naturally.
Conceptualizing the System
The initial challenge was defining the scope. Rather than build a complex RPG ability editor, I focused on delivering a small, functional prototype that solved a clear problem:
"How can I let designers define new abilities without touching code, while keeping the system scalable for different effect types?"
To solve this, I planned the system around:
• Ability Data Assets as modular definitions.
• An Ability Component for executing effects and managing cooldowns.
• A simple UI widget for cooldown visualization.
• Event dispatchers for Blueprint designers to hook into ability execution.
Rather than jump straight into code, I mapped the structure visually using UML diagrams and rough data flow sketches to clarify responsibilities across classes and plan future extensibility.
System Structure
At a high level, the system consists of three main pieces:
UAbilityDataAsset
A simple Unreal Data Asset that stores:
A simple Unreal Data Asset that stores:
• Ability Name
• Cooldown Time
• Effect Type (Damage, Heal, Dash, etc.)
• Effect Value
• FX and SFX references
UAbilityComponent
An Actor Component that:
An Actor Component that:
• Loads and manages abilities assigned via the editor.
• Handles input-based activation.
• Tracks and enforces cooldowns.
• Executes effects based on data from AbilityDataAssets.
WBP_AbilityCooldownDisplay
A basic UI element that displays cooldown timers for each ability in real-time, using event dispatchers from the Ability Component.
A basic UI element that displays cooldown timers for each ability in real-time, using event dispatchers from the Ability Component.
By separating data from execution, I’ve created a clear distinction between what an ability is and how it behaves.
Planning Before Coding
Before touching Unreal, I treated the project like a real development sprint:
• Created Jira tasks and epics to manage priorities and time estimates.
• Wrote Confluence-style documentation for both designers and engineers.
• Defined stretch goals (combo chaining, upgrades) for future sprints.
• Focused early code on scalability and readability, not feature creep.
Using this approach helped me avoid "prototype sprawl" and kept my implementation tightly scoped.