Learn to Mod The Sims 4

A collection of tools, tutorials, and threads useful for getting started with modding and creating custom content in 2021.

Getting Started

Modding any game can be overwhelming, especially if you don't have experience with the underlying technologies like Python, and XML.

The first step is to familiarize yourself with these technologies and how they are applied to the game's resources.

XML

This will be the primary technology you'll need to understand to successfully create any form of custom content for the game. XML is used for most Tuning files, which explain how to the game specific object or interaction should function.

Maxis provides documentation for most Tuning resources which can be found at my TDESC Browser. Maxis may make updates to their code which means their documentation will need to be updated. I will keep the Browser up to date with the TDESC files provided the Gurus on The Sims forums.

Python

A scripting language that powers the simulation code. You will need to understand the rules and syntax to successfully create a Script Mod.

Communities

If there's anything I learned over the past year of modding, join the community and ask for help!

Creator Musings

A wonderful community full of kind and helpful people for beginners and experts.

Lot 51 Community

My personal community to get immediate support on Lot 51 Mods.
Join to talk shop, The Sims, Aliens, or just to chat non-sense :)

Tools

These applications will let you read and edit files related to the game, like packages, tuning files, string tables, images, sounds, effects.

For your first mod, you will only need Sims4Studio.

Tools

Sims4Studio

The BEST all-in-one tool for beginners and experts to search/edit package files and extract game resources.
By Sims4Studio
Tools

String Table Editor & Merger

Allows you to create, edit and merge STBL files right from your browser! You can then export your files and import using S4Studio or S4PE. Be sure to read their instructions before you start.
By Frankk
Tools

PyCharm

A powerful Integrated Development Environment (IDE) for Python. Follow the Python Modding Series below to learn how to setup your modding environment. This will give you suggestions while you type to make it easier to reference EA code.
By JetBrains
Tools

Sims Log Enabler

Useful for finding errors with tuning and mods that do not throw game exceptions but end up not working, also useful when you're testing in your own scripts with sims4.logger
By Scumbumbo
Tools

Sims 4 Image Viewer

Useful tool that specifically targets image resources with a preview. Website is French, but the app supports English
By deevo
Tools

TS4 Sound Tool

Probably the only tool to extract game sound effects and music
By denton47
Tools

Mod Constructor

This is a WYSIWYG (what you see is what you get) tool that will generate tuning for you! Perfect for beginners creating new traits, aspirations, holidays, and more!
By Zerbu

Tuning Tutorials

Tuning

Animation Event Configuration

Useful information for creating "Events" in your animation clips. Explains which hashes are used and default flags for Bones, Effects, Header1, Header2.
By SACRIFICIAL
Tuning

Creating a Buff

A great tutorial on getting started with reading and editing tuning files
By Zero on Patreon
Tuning

Creating Loot Actions

A great tutorial on getting started with reading and editing tuning files
By Zero on Patreon
Tuning

How to Write tests, test_globals, test_anonymous

A great thread detailing the different types of tests and how to edit them in tuning files.
By MizoreYukii on Sims4Studio

General Resources

General

Sims4Studio Tutorials Forum

A great place to search for recent modding tutorials.

Python Scripting Resources

Python Scripting

Get the relative path to your mod

Useful when generating log/config files for your mod.
By Sumbumbo
Python Scripting

The Sims 4 Modern Python Modding Series

A very detailed tutorial to get your scripting environment setup and game code decompiled.
By June Hanabi on GitConnected
Python Scripting

Basic Code Injections

Useful to override or add tuning items without using XML nor overriding complete files
By Deaderpool on Mod The Sims
Python Scripting

Injecting Traits on Sim Add

Useful to figure out how to create "event listeners" and do things when Sims are added
By Frankkulak on Sims4Studio
Python Scripting

Injecting Tests into Interactions

Useful to learn the basics of modifying interaction and buff tuning through scripting
By Triplis
Python Scripting

Injecting Custom Testsets into Interactions

Useful to learn how to create your own XML injector that can make changes to existing tuning files without fully overriding them.
By frankkulak on Sims4Studio
Python Scripting

Script Hot Reloading

This allows you to make changes to your python code without restarting the game. Updates to package xml still need a full restart to take effect.
By Scumbumbo on Mod The Sims
Python Scripting

Working with Household Utility enums and calling methods

Useful to figure out how to work with Enums and overriding methods with python code
By Sigma1202 and Basemental on Sims4Studio
Python Scripting

Advanced Scripting (Working with Immutable Slots)

This is an important tutorial that shows how to modify some code that has become immutable, or unchangable, after it has been processed at runtime
By Scumbumbo on Mod The Sims
Python Scripting

Python sockets for two-way data communication while playing

Useful for intercepting data between the server and client and sending it out of the game, think multiplayer mods
By Real Python

Other Creators Providing Resources

Content Creator

Frankk Mods

A spellcaster with a ton of scripting knowledge!
Content Creator

Mizore Yukii

A spellcaster with a ton of knowledge about tuning, Sims4Studio, and everything else Sims!
Content Creator

RAVASHEEN

A spellcaster with a ton of knowledge about objects, also creates beautiful yet functional Maxis Match CC.

Enjoying Lot 51 CC?

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and to help keep the TDESC Browser up-to-date.