Stats, abilities, talents, classes and skills for Unreal's Gameplay Ability System, with an editor window that shows how they connect.
Flying Donkey GAS is a combat and character foundation built on Unreal's Gameplay Ability System (GAS): attribute sets, a damage formula with real depth, melee and ranged abilities, a ready-made character with first- and third-person cameras, experience and levels, talent trees, classes and subclasses, skills and skill bars. The data that makes characters play differently is written in one editor window, the GAS Toolkit, and Validate finds the mistakes that would otherwise only show in play.
GAS is powerful and famously hard to start with. Flying Donkey GAS gives you a working character on day one, and a window where a designer can make a class, its talents and its skills without opening a Blueprint.
Flying Donkey GAS was built for Oathwake, our co-op survival RPG in development, which runs on it. It is code and tools, not an art pack: it ships no meshes or animations, so it fits any character you bring.
AT A GLANCE
• A ready-made character: abilities, attribute sets, first- and third-person cameras, playable with no input assets
• Attribute sets for vitals, primary stats, offense, defense, survival needs and progression, each switchable
• A damage formula with Added, Increased and More buckets, critical hits and armour
• Melee combos with hit windows, hitstop and camera shake; area attacks; projectiles, including hold-to-draw
• Dodging, directional guarding and hit reactions
• Experience, levels and three point pools: attribute, talent and skill points
• Talent trees, edited as a graph, with a node that opens the choice of a subclass
• Classes and subclasses, skills that unlock by level or points, and skill bars on the number keys
• Tag rules: which abilities block, cancel or require others
• Ability sets that grant a whole kit at once, also from Game Feature plugins
• Survival needs (hunger, thirst, fatigue, temperature), off until you switch them on
• Targeting, PvP rules with flagging and PvP zones, simple hostile and ambient AI, interaction and harvesting
• The GAS Toolkit: Attributes, Talents, Classes, Skills, Balance and Abilities in one window, with Validate
• Generate GAS code: a new attribute set's C++ written for you
• Examples and a 49-page user guide (PDF) included
HIGHLIGHTS
A character that works on day one
Drop the example character in a level, give it your mesh and animation Blueprint (or Epic's free mannequin), and play: health and stamina bars, a class, a talent tree, skills and a heavy attack are wired. Movement and the camera work with no input assets at all; assign your own Enhanced Input actions and they take over. X switches between first and third person, and characters running past never pull the camera in.
Damage with depth
Hits run through one formula: the ability's base damage, plus Added damage, times the sum of Increased percentages, times every More multiplier, then critical hits, armour and damage reduction. The Balance page runs your game's own formula on scenarios you set up (an attacker's damage and bonuses against a target's armour) and shows the hit, the critical hit, the average and the hits to defeat, before you press Play.
Combat abilities
Melee attacks play combos from montages, hit only inside their hit windows, sweep along the swing, pause the moment of impact (hitstop) and shake the camera, and can carry an animation set per skeleton. Area attacks hit everything in a radius. Projectiles launch from the server, and a charged shot draws while held and looses on release. Dodges use root motion and respect collision. A guard component blocks from the front at a stamina cost. A struck character flinches through a hit-reaction ability. Self abilities heal or buff, described entirely as data.
Progression you design, not code
Experience comes from kills or anything you choose and fills levels with attribute, talent and skill points. Talent trees are drawn as graphs: nodes, prerequisites, and a special node that opens the choice of a subclass. Classes inherit from their parents. Skills unlock by level, by points or by themselves, and go on skill bars that the number keys use. Respec is built in.
The GAS Toolkit
Six pages, one layout: Attributes (with each set's switch and Generate GAS code), Talents (the graph), Classes, Skills, Balance and Abilities (definitions, tag rules and ability sets). Every link is a click: a class shows its tree and abilities, an ability shows every class, skill and talent that grants it. Validate checks every page and says what to fix, in plain words.
GAS done the GAS way
Everything is standard GAS: attribute sets, gameplay effects, gameplay abilities, tags. Ability sets grant a whole kit (abilities, input tags, effects, attribute sets) and take it back as a unit. The character is a Game Feature receiver, so a Game Feature plugin can add abilities at runtime, including whole ability sets. Your own GAS setup can use the toolkit for its attributes and abilities too.
For multiplayer games
The character, its abilities and its progression replicate the GAS way, with the server deciding hits, damage, projectiles and guard. Targeting replicates the chosen target. PvP rules give a server three modes (never, always, or by flag), with flagging on at once and off after a delay, and zones where players always fight.
WHAT'S INCLUDED
• The plugin with full C++ source: six modules (core, character, interaction, progression, UI, editor)
• The GAS Toolkit with Generate GAS code
• Examples: a character, a class with two subclasses, a talent tree, a skill set, an ability set, tag rules, a melee ability and a HUD
• A 49-page user guide (PDF), with a ten-minute walkthrough from nothing to a playable class, and a setup README
• Console commands for testing (experience, points, skills, survival), on a cheat manager that ships off by default
• Automated tests, runnable in Unreal's Session Frontend
GOOD TO KNOW
• No meshes or animations are included. Use your own, or Epic's free Third Person template.
• New attributes are C++ (a GAS rule). Generate GAS code writes that C++ for you; you build the project once.
• The AI components are small brains (chase, attack, return home; wander, patrol), not a behaviour-tree system.
• The HUD and stats panel are plain. Skill and talent screens are your game's to draw; the toolkit edits the data behind them.
• Survival needs, derived stats and PvP rules are off until you turn them on.
SPECIFICATIONS & REQUIREMENTS
• Engine: Unreal Engine 5.8
• Platforms: Windows (Win64). The runtime modules are plain C++ with no platform code; only Windows is tested.
• Dependencies: the engine's Gameplay Abilities, Enhanced Input, Modular Gameplay and Game Features plugins, enabled automatically. No other product.
• Network: replicated, server-authoritative; tested with a listen server and clients.
• Code: full C++ source. No C++ needed for classes, talents, skills, balance or abilities; new attribute sets are C++, written for you by Generate GAS code.
• Documentation: a 49-page user guide (PDF, in the plugin) covering install, a first class in ten minutes, every page of the toolkit, every Validate message and troubleshooting.
• Third-party content: None