The most up-to-date guidelines may be found here.
This is post contains general information about preparing your content for submission and Marketplace expectations.
General Marketplace Statements and Submission Process
UE Marketplace Responsibilities
UE Marketplace Buyer/Patron Responsibilities
UE Marketplace Seller/Vendor Responsibilities
Preparing Your Assets
Submission Requirements
Particle Effects
Animations
Blueprints
Meshes
Materials
Textures
Characters
Weapons
Audio
Code Projects and Plugins
Required Levels and Maps
Asset Naming and Folder Structure
General Quality Standard
Restricted Content
Submission Process
File Distribution
We’ll be updating this thread as necessary going forward and provide dates when things have changed.