How the Toolchain Works

PAYDAY 3 modding uses three major pieces that work together.

Custom PAYDAY 3 Unreal Editor

PAYDAY 3 currently uses Unreal Engine 5.5.4. The modkit uses a compatible custom editor and a stubbed PAYDAY 3 C++ project with reflected game types.

The editor provides the development environment in which you create your own assets and Blueprints.

It can also expose supported cooked assets from your installed copy of PAYDAY 3 as read-only reference content.

The modkit does not need to redistribute PAYDAY 3’s base-game cooked assets.

The user’s own installed game provides that content.

CrimeForge

CrimeForge handles PAYDAY-specific editor workflows.

Its responsibilities include:

Creating mods as Unreal plugins.
Creating mods from templates.
Managing mod structure.
PAYDAY-specific authoring tools.
Validation.
Forging mods.

CrimeForge calls its final cook/package operation Forge. Forge cooks the content that belongs to the selected mod and packages only the assets that mod should include.

PDML

PAYDAY MODLOADER is the runtime side of the toolchain.

It provides the loading and integration layer for functionality such as:

CrimeForge plugin mods.
Blueprint and logic mods.
HUD mods.
Custom heists.
Mod settings.
Shared runtime APIs.
Mod initialization.

PDML mods are installed under PAYDAY3/Mods/, keeping community mods separate from the base game’s PAYDAY3/Content/Paks/ directory.

From editor to game

A simplified workflow looks like this:

Your mod-owned assets
        |
        v
CrimeForge plugin mod
        |
        v
Custom PAYDAY 3 Editor
        |
        v
CrimeForge
 create / validate / Forge
        |
        v
Forged mod plugin
        |
        v
PAYDAY3/Mods/
        |
        v
PDML + PAYDAY 3
        |
        v
Runtime mod

Asset replacements may still target game-compatible asset paths inside the mod, while additive/runtime features can require PDML integration.

Cooked Assets explains the distinction in more detail.