Modding and user-generated content tools

Modding and user-generated content (UGC) tools are editors that let players build new levels, assets and games inside an existing game or platform. Some are the studio's own internal tools, released to the public; others are platforms built for creators from the start. The editors themselves cost nothing, though some need a copy of the game.

For an environment artist or level designer they provide a finished game's assets, metrics, lighting and players to build with, which a blank engine does not. This page compares the main options. For general-purpose blockout editors, see level editors and blockout tools; for full engines, see game engines.

#Comparison

#The tools in more detail

#UEFN

Epic released UEFN in March 2023 as "a creative suite for Fortnite creators", built on Unreal Engine, with a new programming language, Verse (MP1st: Epic Games Releases Unreal Editor for…). Epic committed 40% of net revenue from the Fortnite Item Shop and similar purchases to its engagement-based creator programme (MP1st: Epic Games Releases Unreal Editor for…). Fab sells some assets specifically for UEFN, including "Reference Only" versions that give access to an asset through its Verse path (Fab documentation: Licenses and Pricing in Fab).

For artists, UEFN is the closest UGC tool to a studio Unreal workflow: the same editor ideas, real asset import, and Epic's own documentation on greyboxing, which it defines as "the process of making a playable rough draft of a level" (Epic Developer Community documentation: Greyboxing in Unreal Editor for Fortnite).

#Roblox Studio

Roblox Studio is "free to use and has everything you need to start publishing creations" (Roblox Creator Hub: Roblox Studio). Its mesh rules are similar to a studio art brief: individual meshes "can not exceed 20,000 triangles", models should be watertight with no exposed holes or backfaces, use quads where possible, and have non-zero thickness; textures may be basic colour or "modern PBR" (Roblox Creator Hub: Mesh specifications). Working to these limits is good practice for polygon and triangle budgets.

#Minecraft add-ons

Minecraft Bedrock add-ons use resource packs (models, textures, sounds) and behaviour packs (logic) (Microsoft Learn: Minecraft Creator documentation). Microsoft documents custom blocks, custom entities with modeling and animation, and tools such as the Block Wizard, Entity Wizard and Bedrock Editor (Microsoft Learn: Minecraft Creator documentation). The art style is narrow, but the block grid is a strict lesson in metrics and readable silhouettes at low resolution.

#Source 2 Hammer and the CS2 Workshop Tools

Hammer is Valve's level editor for Source 2 games, including Half-Life: Alyx, Counter-Strike 2 and Dota 2 (Valve Developer Community: Hammer). The CS2 Workshop Tools open an Asset Browser with Hammer 5.x, the Material Editor, the ModelDoc Editor, an Image Subrect Editor and Source 2 Filmmaker (Valve Developer Community: Introduction to Counter-Strike 2 Workshop…). In Hammer the usual workflow is to place geometry with the Block Tool, then refine it by editing vertices, edges and faces, with a Displacement Tool for terrain (Valve Developer Community: Hammer Overview).

A competitive map has strict requirements: exact sightlines, cover heights and readability for players who know every pixel of the official maps. See sightlines and vistas and layout and flow.

#Skyrim Special Edition Creation Kit

The Creation Kit is "a free downloadable editor that allows you to create mods for Skyrim", and Bethesda describes it as the same toolset the studio uses internally (Steam: Skyrim Special Edition: Creation Kit). Because it is the studio's own toolset, it is a hands-on way to see how a shipped game's spaces are assembled, including its modular kits. Note the Steam reviews: "Mixed", with 61% of 518 reviews positive in October 2026 (Steam: Skyrim Special Edition: Creation Kit).

#Halo Infinite Forge

Forge is Halo's in-game editor. In Halo Infinite it opened as a beta to all players on Xbox and PC, with a planned launch on 8 November 2022 (Windows Central: Halo Infinite Forge beta: Release date, how…). Windows Central described maps built from "thousands of geometric objects", plus terrain, decorations, effects, per-axis object scaling and a scripting system (Windows Central: Halo Infinite Forge beta: Release date, how…). Forge works entirely with in-game objects, which makes it a pure exercise in layout, kitbashing and set dressing and art passes rather than asset creation.

#What each tool teaches

#Common mistakes

• Ignoring the platform's content rules. Each platform has its own terms for publishing and monetising; read them before you invest months.
• Portfolio pieces made only from stock game assets. They show layout skill, not asset skill (80 Level: How to Approach Environment Art).
• Ignoring the game's metrics. Players notice at once when cover is the wrong height or doors are too narrow. Measure the official maps first; see grids and metrics.

#Further reading and watching