Modding Tutorials

Mods

This is the hub page for tutorials, guides, and reference materials for creating mods for RimWorld. If you are looking for instructions on how to use RimWorld, please check out the general Modding hub.

As RimWorld does not have a formal modding API, nearly all of the information here has been gathered and maintained by the modding community.

NEW: RimWorld 1.5 Mod_Updates - A work-in-progress list of changes datamined by the modding community in the current unstable version of RimWorld 1.5. THERE MAY BE ANOMALY SPOILERS, YOU HAVE BEEN WARNED.

About RimWorld

RimWorld is a multi-platform game written on Unity 2019.4. However, the Unity Editor is not used for creating mods unless you are creating new shaders.

Recommended Software - Editors and other useful software for mod development
Mod Folder Structure - Explore the basic folder structure of a mod
- About.xml - About.xml identifies and describes your mod to RimWorld so that it can be loaded properly
Defs - XML Definitions are used to define and configure content in a way that does not require compiling code
- MayRequire - MayRequire and MayRequireAnyOf are used to conditionally load Defs and list entries based on whether a DLC or other mod is loaded
Localization - Define text strings used for translations and word lists used in name and text generation
PatchOperations - PatchOperations are used to modify XML Defs without overwriting them directly
Sounds - (Needs Rewriting) Adding sound files for mods
Textures - How to create and add textures to mods

XML Tutorials

The following are step-by-step tutorials for creating basic content mods.

Basic Tutorials:

Basic Melee Weapon - How to create a basic melee weapon with a texture mask
Basic Ranged Weapon - How to create a basic ranged weapon with custom sound effects
Basic Plant - How to create a custom plant with both a cultivated and wild variant
Custom Animal (Upcoming)
Simple Building (Upcoming)
Custom Workbench (Upcoming)
Custom Drug (Upcoming)

Advanced Tutorials:

Custom Faction (Upcoming)
Custom Culture (Upcoming)
Custom Trader Type (Upcoming)

C# Guides

XML can be used to create and configure

Decompiling Source Code - How to set up and use a decompiler to read vanilla game code
Setting up a Solution - How to set up a solution for compiling a custom mod assembly
Application Startup - Describes the application startup process and the order in which game data is loaded
Custom Consumable (Upcoming)
Custom Overlays (Upcoming)

Slightly Outdated

Plague Gun - This tutorial was created for RimWorld 1.0 but updated for 1.4. While the exact content is obsolete as you can now accomplish the same result with purely vanilla XML, it is still useful as a crash course for end-to-end mod creation and is here until newer tutorials can replace it.

Uploading to Steam Workshop

You can upload your mod to Steam Workshop by enabling Development Mode from your game Options and then using the Upload option under the Advanced button in the vanilla mod manager.
Note that in order to upload to Steam Workshop, you must own the game on Steam Workshop. Owning RimWorld on GOG or Epic will not work.
Your Preview.png should be a 640x360 or 1280x720 PNG and must be under 1MB. If it is too large, then your upload will be rejected with Error : Limit Exceeded
If you get a OnItemSubmitted Fail error, this usually means that Steam Workshop is having some technical issues at the moment. If it keeps occurring, then the only thing to do is to wait a few hours for it to clear up.
Steam mod descriptions don't use markdown, they use a variant of BBCode. Please check out the Steam text formatting guide.

Note: All of the above tutorials have been cleaned up and reviewed by the #mod-development team on the RimWorld Discord in cooperation with RimWorld Wiki staff editors. Please let us know before creating, adding, or making any major edits to the vetted tutorials and guides section!

Outdated / Under Review

The following tutorials are either out of date or in need of a rewrite. The information in them might be useful but may not be up to standard; please be aware of any potential inaccuracies until they can be addressed.

(Redundant, need to be reviewed and consolidated or removed)

XML tutorials

XML File Structure
Introduction to XML Defs
- XML Def Compatibility
- ThingDef explained
- Weapons_Guns.xml explained. Slightly dated.

C# tutorials

Hello World
Writing Custom Code
Linking XML and C#
Alter Code at Runtime with Harmony - this is a best practice for modifying game code, replacing C# code injection to reduce Mod Conflicts
Adding fields and methods to classes
Mod settings - Add settings to your mod
Def mod extensions - Add (custom) fields to Defs
Custom Comp Classes - A quick overview of what types of Comps there are, and what they're suited for.
ThingComp - Learn all there is to know about ThingComps.
Components - GameComponents, WorldComponents, and MapComponents
Introduction to Def Classes
Using Harmony to optionally patch other mods for the sake of compatibility
TweakValues - Change values on the fly (handy for quick iteration!)
ExposeData - Save stuff
The big ass list of useful classes - A non-exhaustive list of classes you'll use most
Grammar Resolver - PAWN_objective, PAWN_possessive? Find out what it all means here.
ExampleJob - Mehni's top to bottom breakdown of Jobs.
Config Errors - Provide configuration issues to the user on startup.
Debug Actions - Call methods from the debug menu
Getting started with RimWorld modding on Linux

Art Tutorials

Artstyle - Officially unofficial guide to RimWorld's Artstyle
Ekksu's guide to creating RimWorld animals
ChickenPlucker's guide to creating apparel
Seraphile's guide to masks

Under Construction

These are currently unfinished and need to be cleaned up or removed

Dangerously Outdated

RimWorld 1.3: XML Mod Creation
Assembly Modding
The Plague Gun tutorial originally by Jecrell, updated to 1.1+.
Modding Tutorials/Xenotype template originally by Ryflamer

External Links