Test Steam players in same computer
Between Players
Instead of using VMs or multiple computers, which can be time-consuming to test because you have to switch between machines each time and send files for each modification, which, in my opinion, is almost absurd given the time development already consumes.
I propose other solutions when you want to save time on development to test your multiplayer game with multiple Steam accounts in standalone mode in one computer and without vm
Sandboxie
Sandboxie can launch your applications in isolated mode, which is convenient because we'll be able to launch a second Steam account and your Unreal game in an isolated environment to simulate two Steam players
Since you're simulating multiple applications on the same computer, it goes without saying that you need to have a powerful machine to handle it!
Sandboxie examples
I'll let you train yourself on Sandboxie; nevertheless, here's an example of how I use it at home:
For example, I usually launch Steam first to simulate a second player on the machine. Then, based on my tests, I decide to launch my UE5 project in standalone mode without shipping, or with shipping if necessary. That's why I have several instances.
You'll also notice that I can test my dedicated Steam servers in the same way!
For example, to launch my game in standalone mode without needing to package it to save time, I can use this command:
"C:\YourUEPath\Engine\Binaries\Win64\UnrealEditor-Win64-DebugGame.exe" "C:\YourGamePath\YourGame.uproject" /YourMap.YourMap.umap -game -windowed -log=SomeOtherLogFile.txt
That's actually what I've put in my UE_Test_Title shortcut.
Sorry for the bonk image, but I can't show all my information ^^
I wrote this article quickly despite the limited time I had (So, I didn't have time to replace them with fake paths)
Example of usage on my game !
The player 2 in sandboxie (1 Steam running and 1 Standalone uproject file):
In game Screenhot :
Youtube Video :
In the video, I also demonstrate an example of a running dedicated server! Typically, after testing, I run my dedicated server on Linux in a local Docker container and then deploy it to a remote Linux server.