Beginning next month, Rocket League will feature Steam Workshop support, allowing players to upload and download custom levels straight through Steam.
A very active modding community for the game already exists on the subreddit RocketLeagueMods, and the addition of this update will allow easier access to them for all players. Once the update is live, Psyonix will provide creators with a Steam Workshop Uploader Tool which will allow them to upload their levels. They will need to provide a name for their creation, a brief description of it, the files of the level itself, and preview images for it to be eligible.
Once in the Workshop section hit the subscribe button next to any level you wish to play and Steam will automatically download it. Next you’ll need to start up Rocket League and click on “Extras” in the main menu and then click “Workshop”.