Correction: Steam was required to play the Steam version...which, until the game was released on GOG last year, was also the only version. The GOG version does not have any serial key or (as far as I know) product number.

I'm not sure what you mean by "wanted to play over Steam". If you're talking about playing multiplayer with people using the Steam version, then I believe that's still possible...but since 1.3's multiplayer "lobby" or whatever is powered by Steam, you'd probably have to set things up the "hard" way. (I've never played multiplayer, and I don't use Steam, so I can't say how accurate this info is, and I sure can't give any additional info on that front.)

If you were talking about buying the game here and redeeming it on Steam, though, then you might as well ask for a refund, as GOG doesn't provide Steam keys for any games they sell, as they are trying to compete with Steam. I don't imagine adding the GOG version into your Steam library as a non-Steam game would give the benefits of the Steam version, either.

I can't help you at all with the Linux stuff, I'm afraid. Hope the rest was somewhat helpful, though. : )

Actually these days, Ubuntu is pretty odd and out there on its own, rather than Fedora, Mint, or Debian.

Here you go for a smooth automated install process, designed for Debian but compatible with Ubuntu:
Install Terraria on Debian/Ubuntu/Mint/etc.

Thank you for the info. I will get back to you and tell you how it goes. I would also be delighted for feedback from people on alternative means of playing this online.

The point is taken about Ubuntu really being out for itself, and I cannot stress highly enough how frustrating it is to have Playonlinux with its long list of games (GOG being referred to with many) that don't work or at least require some fiddling... the "in development" disclaimer comes up far too often.

The helpful Ubuntu community has gone down in my estimation somewhat, as they insist that any Windows game can be easily installed on this O.S. I found out quite early on that this is not the case.

Then again, it is wonderful when one finds that, say, Plainscape Torment starts straight off.

I don’t own Terraria so I don’t know how it goes for online play.
Should anything seem amiss with the script I linked you to, please post about it in the dedicated thread and I’ll forward your message to the author of this script so it can be updated.

I carefully followed the instructions as well as others. The commands are understood, but I am not granted privileges to the root. I'm asking what you know about this prior to my searching, as you never know - - it's very odd as, yes, I am the admin of compootah here. Linux Mint is awful, if in need of a very low-fi O.S, I recommend Xubuntu. It's just lovely.

Bar the gaming issue, I regard KDE (a different shell for unity) as Windows only better. IT would be delightful for a version that can partake of the Android pool of apps, as this is a version of Linux after all.

I think it's a case of independent developers not caring about Ubuntu. Just observe the requests for a version of, say, Path of Exile: Linux is simply not considered.

If you're an admin user in Ubuntu (along with most linux distributions), you can give root privileges to a single command by preceeding it with "sudo". Note that you might be prompted to type in your password - this is normal.

sudo <command>

For example, the following will create a file at /tmp/test owned by the root user:

sudo touch /tmp/test

You can also run the following to switch to a root shell, so every command you type will be executed as root.

sudo su -