Game development glossary, in plain words

124 terms you will meet while making a game in Unreal Engine 5, Character Creator and Blender, each explained without jargon.

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.uproject file
The file that opens your Unreal project. Its path tells Duke where your project lives.

A

Accessibility
Options that let more people play: subtitles, bigger text, remappable controls, colorblind modes and less camera shake.
ActorMixer
A Character Creator tool that blends up to six characters into a new face and body, like mixing paint. It is how a few seed characters become thousands of different people.
Adaptive music
Music that changes with what is happening in the game, rising into combat and calming down after.
AI agent
An AI that does a multi-step job on its own, such as placing a district of buildings, then checks its work and reports back for your approval.
Ambience
The background sound of a place: wind, distant crowds, birds, machinery.
Animation Blueprint
The Unreal graph that decides which animation plays and how animations blend, for example walk into run.
Art direction
The one or two sentences that define how everything should look, used to keep every asset consistent.
Asset
Anything the game uses that is not code: a model, animation, texture, sound or music track.
Auto Setup
Reallusion's free plugin that sends a Character Creator character into Unreal or Blender with its materials built for you.

B

Bark
A short line an NPC says on its own, like "Watch it!" or "Fresh bread here!"
Biome
A type of natural area with its own plants, rocks and ground, like desert, forest or volcanic flats.
Blender
Free professional 3D software for modeling, sculpting, UVs, texturing and rigging.
Blockout
A level built from plain gray boxes to test sizes, routes and fun before any real art is made.
Blueprint
Unreal's visual scripting: you build game logic by connecting boxes (nodes) instead of typing code.
Bottleneck
The one thing slowing the game down the most. Fixing anything else barely helps.
Budget
A limit you set in advance, for money, time, frame rate or memory.
Build agent
A small Duke program that runs on your PC. It reports your hardware and tools, and builds and packages your game when you press Build.

C

Camera
The player's point of view. Third-person cameras follow behind the character.
Character
In Unreal, the Character class is the piece that holds a moving person: its body, movement and abilities.
Character Creator 5
Reallusion's character software (CC5). It builds realistic, fully rigged people from sliders, presets and photos, ready for Unreal.
Checkpoint
A saved spot the player returns to after dying.
Color grading
Adjusting the final colors of the image to set a mood, like a film colorist does.
Commit
A saved snapshot of your project in version control that you can return to later.
Cook
Unreal's step that converts your project's files into the compact format the finished game loads.
Copyright
Legal ownership of a creative work. It decides who may copy, sell or reuse it.
Crowd
Many NPCs simulated together as a group so thousands can exist at once.

D

Data layer
A switchable layer of a World Partition map, used for world states such as a town before and after a fire.
DeLight
A Headshot tool that removes the lighting and shadows baked into a photo, so the skin reacts correctly to game lights.
Displacement
Using a texture to push a surface in and out for fine detail like pores, wrinkles or cracks.
District
A named part of your world with its own style and mood.
Ducking
Automatically lowering one sound (like music) when a more important one plays (like dialogue).

E

Enhanced Input
Unreal's system for mapping keys, mouse and controller buttons to actions like Jump or Attack.
Expansion loop
Duke's repeating cycle after the vertical slice: measure the gap, build more in a sandbox, check it, you approve, merge, repeat until every requirement is met.

F

Facial capture
Recording a real person's face with a camera and turning it into facial animation.
Foley
Everyday sound effects like footsteps, cloth rustle and objects being handled.
Frame rate
How many images the game draws per second (fps). 60 fps feels smooth; under 30 feels choppy.

G

Game loop
The complete cycle a player repeats: start, play, win or lose, try again.
Game rules
Exactly how the game behaves, written so each rule can be tested.
GameMode
The Unreal piece that holds the rules of the game: how you win, lose and respawn.
Gameplay framework
Unreal's set of building blocks (Character, PlayerController, GameMode, GameState) that keep a game organized.
Git LFS
An add-on to Git that stores big files like models and textures efficiently.
Global illumination
Light that bounces off surfaces onto other surfaces, the main reason a scene looks real.
Graphics card
The part of the PC that draws the game (GPU). It matters more than anything else for Unreal Engine.

H

HD base
Character Creator 5's high-detail starting body, with up to 16 times more mesh detail than earlier versions.
Headshot 3
A Character Creator plugin that uses AI to build a realistic 3D head from a single photo of a face.
Heightmap
A grayscale image where brighter means higher, used to shape terrain.
Hero asset
A model players see up close and often, so it is made by hand to the highest standard.
Hit detection
The code that decides whether an attack actually touched its target.
Hitbox
An invisible shape used to detect hits.
HLOD
Hierarchical level of detail: a simplified version of a whole area shown when it is far away.
HUD
Heads-up display: health, ammo, objectives and minimap drawn over the game.

K

Keyframe
A pose an animator sets at a moment in time; the software fills in the motion between keyframes.

L

Landmark
A memorable location players navigate by, like a tower or a lake.
Landscape
Unreal's system for large outdoor ground you can sculpt and paint.
Language model
The kind of AI that writes text and holds conversations (LLM), used here for NPC dialogue.
Latency
The delay between asking for something and getting it, such as an NPC answering you.
Level
A playable space or map in the game.
License
Permission to use something you did not make, with rules about how. Keep every license file.
Likeness
How closely a 3D character resembles a real person.
Lip sync
Moving a character's mouth to match spoken audio.
LOD
Level of detail: simpler versions of a model used when it is far away, so the game runs faster.
Lumen
Unreal's real-time lighting system for bounce light and reflections.

M

Mass AI
Unreal's system for simulating thousands of characters, cars or creatures efficiently.
Material
Instructions that tell the engine how a surface looks under light: skin, cloth, metal, wet stone.
MCP plugin
An experimental Unreal 5.8 plugin that lets AI agents operate the editor, such as placing objects or running tools, with your approval.
MegaLights
An Unreal 5.8 lighting feature that allows many shadow-casting lights at once, ideal for cities at night.
Megascans
A large library of photoscanned real-world surfaces and objects, available on Fab for Unreal projects.
Mesh Mode
A Headshot mode that turns an existing 3D head, such as a scan or sculpt, into a rigged character head.
Mesh Terrain
An experimental Unreal 5.8 terrain system that can make overhangs, caves and floating islands, which a normal landscape cannot.
MetaSounds
Unreal's system for building sounds and music that react to the game.
Mission
A task with a goal, a place and a reward that moves the game forward.
Mix
Balancing the volume of every sound so the important ones are clear.
Modular kit
A set of building pieces (walls, floors, roofs, doors) that snap together into many buildings.
Modular wardrobe
Clothing split into interchangeable pieces so outfits can be mixed automatically.
Morph
A slider that reshapes a character's body or face.
Motion capture
Recording a real person's movement and turning it into animation.
Multiplayer
More than one player in the same game over a network. It affects every system, so it is decided early.

N

Navigation mesh
An invisible map of where characters can walk, so NPCs can find routes around obstacles.
Normal map
A texture that fakes small bumps and detail on a surface without adding polygons.
NPC
Non-player character: anyone in the game the player does not control.

O

Open world
A game world the player can roam freely instead of following fixed levels.

P

Packaging
Turning your Unreal project into a standalone game that runs without the editor.
Patch
An update that fixes bugs or adds content after release.
PCG
Procedural content generation: Unreal places trees, rocks, buildings and clutter by rules you set, instead of by hand.
Photogrammetry
Making 3D models from many photos of a real object.
Playtest
Watching someone play your game to see where it confuses or bores them.
Plugin
An add-on that gives Unreal extra features.
Point of interest
A spot in the world worth visiting: a camp, a cave, a shop.
Procedural
Made by rules and randomness instead of by hand, so it can produce a lot of variety.
Profiling
Measuring exactly what takes time in each frame, using tools like Unreal Insights.

R

Reference board
A collection of images that show the look you are aiming for.
Regression
Something that worked before but broke after a change.
Requirements
The numbers your finished game must reach, such as districts, NPC looks and frame rate.
Retargeting
Moving an animation from one skeleton to another so it plays on your character.
Retopology
Rebuilding a model's polygon layout so it is lighter and bends cleanly.
Rig
The skeleton and controls inside a model that make it move.

S

Sandbox
An isolated copy of the project where AI agents work, so nothing touches your real project until you approve.
Save game
The stored progress of a player: checkpoints, items, settings.
Scope
How much the game includes. Keeping scope realistic is the number one reason solo games get finished.
Sculpting
Shaping a 3D model like digital clay.
Seed cast
The small set of hand-made base characters the variation system mixes into thousands.
Sequencer
Unreal's tool for cutscenes and trailers, like a film editing timeline.
Shipping build
The final, optimized version of the game meant for players.
Side quest
An optional mission outside the main story.
Skin weights
Which bones move which parts of a model or its clothes.
Smart Object
A place NPCs know how to use, like a bench to sit on or a counter to work at.
Socket
A named attachment point on a skeleton, for example the hand where a sword is held.
Species
A kind of being in your world, human or not, with its own look, movement and voice.
Spline
A curved line you draw in the editor to lay roads, rivers or fences.
State Tree
Unreal's system for NPC behavior: states like idle, alert, chase and attack, and the rules for switching between them.
Streaming
Loading parts of the world as the player approaches and unloading them behind, so huge worlds fit in memory.
Subtitles
On-screen text of what is said.

T

Texture
An image wrapped onto a model to give it color and surface detail.
Topology
How a model's polygons are arranged. Good topology bends cleanly at joints.
Turnaround
Concept art showing a design from the front, side and back.

U

Unreal Engine
Epic Games' engine used for Star Wars Outlaws-class graphics. Free until a game earns $1 million, then a 5% royalty.
UVs
A flat layout of a 3D model's surface that says where each part of a texture goes.

V

Variation
Differences between copies, so no two NPCs, buildings or trees look the same.
Version control
A system (like Git) that records every change to your project so you can undo mistakes and recover old versions.
Vertical slice
One small part of the game finished to final quality in every way. It proves the game can be made and sets the bar for everything else.
Voice design
Creating the sound of a character's voice, often with AI voice tools.
VRAM
The graphics card's own memory. Unreal's detailed worlds need at least 8 GB.

W

World Partition
Unreal's system that splits a big map into cells and loads only those near the player.