Set up your creator tools

Install Source 2 Viewer and the community CSDK 12 tools, create your first addon, and learn where your source and compiled files go.

Beginner

This guide installs the two tools almost every Deadlock mod needs and creates your first addon. Set up mods on your PC first, so you can test what you make: use Deadlock Mod Manager or install mods by hand.

What you need

Windows PC

Deadlock on Steam

latest versionFree disk space

The creator tools run on Windows only. Keep Steam open whenever you use CSDK 12. You need free disk space for the tools.

What you will install

Valve has not released modding tools for Deadlock, so creators use two free community tools. Tools overview lists the others.

Source 2 Viewer

Opens the game's files. Previews models, textures, and sounds. Turns compiled files back into files you can edit.

CSDK 12

Valve's Source 2 tools, adapted for Deadlock by the community. Compiles your edited files so the game can read them.

Want to try first? Use a browser tool

Two unofficial community tools build simple mods in your browser and give you a ready VPK file:

Deadlock Forge

By Sirsyorrz. Sounds, hero portraits, ability icons, and item art.

DeadMod

By RedMser. Textures. You still need Source 2 Viewer to get the original texture.

The Deadlock Forge home page with three tools: Sound Forge, Item Forge, and Texture Forge

The DeadMod page with a file path field, a Choose file button, the mod file name, and Save mod as VPK

They only cover simple swaps. Install their VPK like any other mod. Make mods without installing tools shows how to use them.

Install the tools

Install Source 2 Viewer

Source 2 Viewer is free and open source (MIT), made by the ValveResourceFormat team.

Open s2v.app in your browser.
Click Download dev build, the small link under the main download button. Deadlock fixes land in the dev build first, and current guides use it. If you pick the normal release, use version 20.0 or newer.
Put the download in its own folder. Source 2 Viewer has no installer.
Open Source2Viewer.exe.

The s2v.app home page with the main Download button and the Download dev build link under it

Install CSDK 12

CSDK 12 is an unofficial community tool

Valve did not make CSDK 12 and does not support it. It repackages files from Valve's Counter-Strike 2 Workshop Tools with community fixes. Download it only from the community page linked below.

Open the CSDK 12 page on the Deadlock Modding Notes site.
Click Download in the Installation section. You get Reduced CSDK 12, which leaves out the full game files. You do not need them for sounds, textures, icons, or models.
Unzip it to a short path, such as C:\Reduced_CSDK_12.
Skip the Full Game Files steps on that page. Beginners do not need them.

The Installation section of the CSDK 12 page on Deadlock Modding Notes, with the Download link and a warning about OneDrive folders

Never unzip it on your Desktop or in Documents. OneDrive often syncs those folders, and that breaks the tools. Keep it out of the Deadlock game folder too: a reinstall can delete it, and it gets mixed up with real game files.

First launch

Start Steam. CSDK 12 does not open without it.
Open csdkcfg.exe in your Reduced_CSDK_12 folder. This is the launcher, also called the Configuration Tool.
Leave the binary picker in the top left on bin.

Older downloads used a different launcher name. If csdkcfg.exe is missing, check the CSDK 12 page.

The binary picker has four choices:

Choice	What it does
`bin`	The normal tools. Use this one.
`bin_tools`	Previews some particle effects that crash `bin`, but crashes on some model compiles. Switch back after.
`bin_server`	Needs the full game files you skipped. It will not start without them.
`bin_cs2`	Only for compiling maps.

Leave the No Addon launch option off. That mode can overwrite the tool's own base files.

Create your first addon

An addon is the project folder for one mod.

Click Create New Addon in the launcher.
Type a name in lowercase, with no spaces or special characters. Example: firstmod.
Select your addon in the list.
Click Launch Tools. A console window opens first, then the Asset Browser.

Right-click an addon in the launcher to see its menu:

Menu item	What it does
Explore Content Folder	Opens the folder for your source files.
Explore Game Folder	Opens the folder for your compiled files.
Duplicate	Copies an addon, such as a template.
Compile All Assets	Compiles every file in the addon.
Create VPK	Packs the addon. Pack your mod into a VPK uses a different, tested method.
Delete	Removes the addon.

CSDK 12 also ships template addons, such as a Billy audio template and a hero image template. The first-mod guides show when to use them.

Content folder and game folder

Every addon has two folders inside Reduced_CSDK_12: content/citadel_addons/<addon>/ for the source files you edit, and game/citadel_addons/<addon>/ for the compiled _c files that go in your mod.

The content folder holds source files such as example_sound.wav. CSDK 12 compiles them into the game folder at the same path, as example_sound.vsnd_c.

Three rules:

Put each file at the same folder path it has in the game. A file the game keeps in sounds/vo/ goes in content/citadel_addons/<addon>/sounds/vo/.
The tools watch the content folder and compile new files into the game folder on their own.
When you pack a mod, copy from the game folder, never the content folder.

Image and audio editors

Any editor that saves the right file types works. These are free:

GIMP

Images. Photoshop works too. Save as PNG, TGA, or PSD.

Free Audacity

Sounds. Export as WAV or MP3.

Free Notepad++

Small text edits in tool files.

Free VS Code

Small text edits in tool files, if you prefer it to Notepad++.

Free

Later: Blender for model swaps

You do not need Blender for sounds, recolors, or icons. For model swaps, install Blender 5.x and FellOffFuji's BlenderSource2Tools add-on, which exports your model in the DMX format the tools read.

Blender and add-ons

Downloads and setup for Blender and BlenderSource2Tools.

Later

Quick check

Test both tools before you start a mod.

Open Source 2 Viewer and click File, then Open.
Open game/citadel/pak01_dir.vpk in your Deadlock folder. In Steam, Manage, then Browse local files opens that folder.
Open only pak01_dir.vpk. Source 2 Viewer reads the numbered pak01_000.vpk files with it.
Expand sounds or panorama and double-click a file to preview it.
Open the CSDK 12 launcher, select your addon, and click Launch Tools.
Wait until the Asset Browser opens.

If both tools open, you are ready for your first mod.

Common problems

Your addon is missing from the launcher. The name has a capital letter, a space, or a special character. Rename the folder in both content/citadel_addons and game/citadel_addons. Then click Refresh addons list.
The tools do not start. Start Steam first. Move the Reduced_CSDK_12 folder out of OneDrive folders.
The game will not find a match. Valve blocks matchmaking while tools mode runs. Close CSDK 12 before you queue.

Errors when making mods has more fixes.

Next steps

Make your first mod:

Replace a sound

Beginner

Start here. Swap one ability sound or music track.

Recolor with material values

Beginner

Change a hero's colors without painting a texture.

Replace portraits, icons, and item art

Beginner

Swap hero portraits, ability icons, and item art.

Want to know how the game loads your files first? Read How Deadlock mods work.

Credits

This guide is based on the work of these creators. Check out their original guides.

Guide: CSDK 12 from Deadlock Modding Notes.
Tool: Source 2 Viewer by the ValveResourceFormat team.
Guide: Neutral's General Guide for Modding Deadlock by Neutraldrift.
Guide: From Start to Finish (Fuji's Asset Replacement Guide) by Fuji (FellOffFuji).
Guide: How I Make Shiny Metal Materials by ShockHub.
Tools: Deadlock Forge by Sirsyorrz and DeadMod by RedMser.

Edit on GitHub

Set up your creator tools

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