For a lot of people, this will be as plug-and-play as ever. Just running “sudo apt install steam”, and done. I did however have some issues with it. It seemed to be installed, but when I wanted to open it, it needed to fix packages called “libc.so.6”, “libgl1-mesa-dri:i386 “, “libgl1-mesa-glx:i386”, “libc6:i386”.
That did however not work, it couldn’t find it. Long story short, there was something wrong in my sources.list (/etc/apt/). It seems like it had an outdated line, which was why it failed to connect. Replacing the
security.debian.org line, fixed it.
I replaced it with this (commented out the old):
deb http://security.debian.org/ stretch/updates main contrib non-free
And bam, all good.
Found the solution here: