How to Install American Truck Simulator Multiplayer
Step 1: Register an Account
First, we need to register an account with TruckersMP.com. You will need to tie your steam account with it as well.
Step 2: Download The Mod
If you are not logged in, do log in and then head over to the download page. You will find a green button that says Download Now. Once downloaded, extract it and keep it ready for the next step.
Step 3: Matching The Version
In order to play the game online we have to have the exact version required by TruckersMP.com. From the download page, you will see "Current Versions Supported By Our Mod". ETS stands for Euro Truck Simulator and ATS stands for American Truck Simulator.
Note down the version needed and head over to steam. Find Euro Truck Simulator. Right Click, Properties, and head over to the Betas Tab. From the droplist select, "opt out of all beta programs". The game might start updating.
Step 4: Installing MP Mode
Now Double-Click on the file we extracted earlier. Go with the installation flow. You are able to choose ETS or/and ATS as well. Once that is done, you can Double-Click on the desktop icon "TruckersMP". You will have two buttons "Launch ETS2", and "Launch ATS"
Step 5: Login & Get Driving
Once you choose your game, the game will start. Log in with the TruckersMP account select a server and Get Driving.