Preamble
Okay, to connect to the QC:DE server, you'll need a few things:
- To download and install Zandronum
- To get an IWAD/PWAD for DooM (or related games) and put it in the correct directory
- To download and install the Quake Champions: DooM Edition files
- To either connect directly to the server, or (recommended) use the DoomSeeker game browser to connect (I'll note why)
Zandronum
You can find the Zandronum downloads here. As most will be playing on a Windows system, you'll want that first download listed as Installer (Bundled with Doomseeker). Run the installer, choose where you want to install Zandronum (I recommend not using the default ... it's up to you), make sure that the Portable installation checkbox is unchecked, and the Associate with PWADs checkbox is checked. Click Install and complete the installation.
Secure the WAD!
C'mon, I KNOW you must have an old copy of DooM, DooM II, Heretic, Hexen, Strife, et. al. (even Chex Quest will do) laying around to provide you with an IWAD file, right? Well, while you go looking for that old disc (where ever you might have buried it ... my copies of Ultimate DooM, Heretic, Hexen, and Strife are up on the shelf behind me ... misplaced my DooM II somewhere ... going to have to rectify that) you can find a DooM II IWAD here. GoG has DooM II for sale as well, and it's regularly $5, and often discounted down to $2 or less. You can just dump the IWAD file in the directory where you installed Zandronum.
Quake Champions: DooM Edition mod
You can find the QC:DE mod files at it's homepage on ModDB. As of writing this, 2.7 is the Stable release, and 3.0 is in Beta. I'm running 2.7. If you use DooMSeeker, you won't need to manually download or install these files, so that's all I'll say here.
DooMSeeker FTW!
Okay, when you installed Zandronum, it also installed DooMSeeker. In the directory you directed Zandronum to install into, there is a directory called Doomseeker, and in there is a doomseeker.exe file. The Zandronum and DooMSeeker applications should have been created as shortcuts somewhere, but if they weren't, this is where you'll find them. DooMSeeker does magic -- it is the default Zandronum game browser. It will make sure you have the same version of the game client as the server, ask you where your IWAD is, and auto-download any mod/map files you need auto-magically, and connect you to the server. It shows how many seats are open on the server, how many bots, players, and specators there are on the server. Use it.
Server Information
Server Name: --+[ QC:DE for BarsooM ]+--
Server Link: thuria.barsoom.cc:10666
Just use the Search field in DooMSeeker (in the upper right-hand corner) and enter barsoom there. It will search through all of the servers and find the server there.
Now, oh yee faithful, go forth, and frag in my name!
Postscript:
dbthanatos has a number of good videos related to QC:DE on his YouTube channel. Most importantly, you'll find Part 1 and Part 2 of his guides for installing and configuring QC:DE to get the best out of the experience of playing the mod. I recommend a watch-through.