Here's my long overdue second installment of the Masters of Doom Files - interview excerpts from my book on John Carmack and John Romero, co-creators of Doom and Quake. In this bit, Carmack discusses his first brush with user-created modifications. It happened shortly after the release of their seminal first person shooter, Wolfenstein 3-D.
JOHN CARMACK: We were seeing some of the early mods for Wolfenstein even before Spear of Destiny shipped. The way people had to do that, you had the data that Wolfenstein shipped with and they had to write tools which would patch the data files and replace the stuff with that. One of the things with the early aspect of Doom was that we would have way that you could add things to it without having to change the original stuff. Once someone patched their stuff, they can’t go back to the original one without reinstalling it. We consider that a bad thing.
It wasn’t like we were shocked by the Wolfenstein mods. People had always hacked games. When I was a kid, I would get out the sector editor and find out where my ultima character lived on disc and give him 255 spells and stuff like that. We knew people would do that. When people started replacing the graphics, they put Barney in instead of the boss and have it singing the I Love You song instead of the guttentag greetings. And then people draw different wall tile graphics.
It all seemed pretty obvious things but there was always this sense of gratification that sure people can do this. But if they do something that makes you smile, there’s a level of gratification there. It’s like, we provided this and someone took what we did and made something neat with it and I smiled when I saw it. Or it’s like I played through their level and I had fun with it.
The way the data was accessed in Doom was specifically designed to be extensible. Because of Wolfenstein mods, Doom had this extensible data loading facility which allowed people to add data in without modifying the original stuff. That’s all that happened because of it.
I put in this facility so people can do this stuff in a non-destructive way. It took a little time for me, but it was clear to me that if people are going to continue to do this -patching things - I’m going to give something so they don’t need to patch. It would allow people to have multiple add-ons without stepping on eachother’s toes. I did have visions that people would…make lots of levels. People can always play through levels more and more. Making monsters is tougher. There never were that many monsters in Doom because you had to draw all the rotations.
I had a good clear idea of what was going to happen with that, but I did underestimate how the support for all the Doom stuff was going to be. I thought it’d be restricted to your hardcore technical geek hacker types. We still didn’t have user-friendly tools. I was surprised at the scope and depth of it. The Star Wars [mod]…if you look back at it, it was levels that had some new graphics and sound, it was just a matter of replacing them all. That was more than I expected. It was clearly using the facilities that I laid out.
