This is a guide on how to play Doom I, II, Hexan, Heretic and Strife on modern day computers (With online multiplayer support for Doom I and II). This also includes some Doom III mods to make the game worth playing.
Before I begin, I want to highly suggest at least trying Skulltag online, it has an active community and very good online play. More in the Skulltag section.
As many of you probably know, Doom was the second first person shooter made. It was published by ID software, who also made the original first person shooter, Wolfenstein 3d. Although the graphics are extremely dated, it still holds up as one of the greatest games of all time. It defined first person shooters, and I highly recommend trying it out.
If you want to play any of the older ID software games like Doom on today's machines, you need the original .WAD files (Contain all the game information) and a port. There are several ports to choose from, but in my experience there are only three you can really go with, depending on what you want out of them.
Those three are Skulltag, Zdoom and Jdoom.
Skulltag is what you want if you're after bots, alternate game modes and active online play.
Zdoom is for highly sophisticated mods and scripting functionality.
Jdoom is for major HD graphical enhancements while retaining the fast-paced style of Doom.
Here are some summaries of each port:
Now, onto Doom III. This game was a huge dissapointment to many, but there are two mods out there that change all that: Perfected Doom III and Sikkmod.
Perfected Doom III is the combination of several mods, including an older version of Sikkmod. It would take forever to list every feature, but here are a key few: Ironsights for all weapons, zombies only die from headshots, increased enemy AI, new enemies/maps/bossfights, new weapon (Supershotgun), alternate fire button for all weapons, HDR, Bloom, high-rez textures... It's what the game should have been. The latest version is 6.2.1.
Sikkmod is a bit more in depth options wise, it adds all the graphical enhancements Perfected Doom 3 does, but has several pages of options. Weapon mag size, enemy health (Original, realistic, Doom II), body location damage, it even has options to randomly spawn in enemies on the map at random time intervals to keep you on your toes.