It comes with native cooperative and deathmatch support, while modern source ports add. Players beyond the first are superfluous. Doom is one of the first games that popularized online multiplayer. Almost all non-deathmatch PWADs are set up for a single player, with the co-op game modified, if at all, to include more monsters and MAYBE a co-op exit. If these don't give you enough tips, search youtube for something along the lines of 'Doomseeker server setup. Justification : The reason no one plays co-op Doom is that its unnecessary. I can't give much help here, as there's a lot of ins and outs, but here are some links that should help you: Next, you'll need to become acquainted with Doomseeker, and so will your friend. Just look at your router's model number (should be somewhere on the router's backside sticker). You'll need to know how to open a port on your router, or set your router to DMZ mode unfortunately, this will be vague from me, as every router is different in how to change its settings, and how to log into it. It allows you and friends to directly connect to each other, instead of fiddling with the ever-unreliable Hamachi. This program allows you to host servers and edit many settings, such as max player/clients, friendly-fire, even a custom map rotation.

When you install Zandronum, it should come packaged with a program called Doomseeker.

Is doom co op