The D&D game that inspired Doom

[Thales]

A few weeks ago, I attended the Strange Loop Conference, a well-regarded tech conference in St. Louis. The keynote speaker on the first day was John Romero, one of the founders of id Software, the studio behind such major games as Wolfenstein 3D, Doom, and Quake. Much of the talk was about the software design principles that guided id Software (and which did not seem especially broadly applicable), but a lot of it was Romero's personal story of the journey he and his friends went on. When talking about Doom, Romero mentioned that the game had been inspired by the studio’s demon-infested D&D campaign (as well as the movies Evil Dead and Aliens). In the Q&A, I asked Romero if he could share a bit about that D&D campaign.

He said that the setting hadn’t been like that at first. Romero told us how John Carmack, the programming genius behind id’s success, was also a superb dungeon master who built an intricate setting full of detailed and interconnected characters and politics. The party members had split up to escape from some unspecified pursuers, and Romero’s character hid in an extradimensional castle occupied by an allied wizard who had a book, the Demonicron, that let him summon and bind demons. One day, as Romero’s character was studying under the wizard, a demon the wizard had conjured contacted him telepathically, promising fancy magic items if given the book. The next time that demon is summoned, Romero’s character backstabbed the wizard and tossed the demon the book. It broke free, grew to a massive size, and while it did give Romero’s character the promised magic items, it made clear that it had not also promised him safety. Over the next two months of campaign sessions, the demons flooded out into the world, killing off all the party’s characters and all of Carmack’s elaborately-crafted NPCs until the setting was basically destroyed. And then they stopped playing D&D. But they got Doom’s Phobos Anomaly out of it!

[animorte]

I like to think that there are FAR more stories we are familiar with in the mainstream that were inspired from the events directly from a game of D&D they were playing. They just don't often reveal that was the birth of the concept.

[The Glyphstone]

I like to think that there are FAR more stories we are familiar with in the mainstream that were inspired from the events directly from a game of D&D they were playing. They just don't often reveal that was the birth of the concept.

In the last campaign I ran (Rogue Trader), I ran an adventure that was subtly but unmistakably a Doom ripoff/homage, so it comes full circle.

[animorte]

In the last campaign I ran (Rogue Trader), I ran an adventure that was subtly but unmistakably a Doom ripoff/homage, so it comes full circle.

Agree with that. The very first character I ever made in D&D was my best interpretation of Kvothe. I’ve seen put together many different ideas inspired directly from one of my favorite books/games/shows/movies.

[Cespenar]

That's a pretty interesting hidden anecdote actually.

Also, to think that we could have gotten a fantasy RPG with deep worldbuilding instead of Doom.

[Fyraltari]

Also, to think that we could have gotten a fantasy RPG with deep worldbuilding instead of Doom.

The Elder Scrolls is exactly that and was based on the developpers' D&D campaign (originally).

[warty goblin]

That's a pretty interesting hidden anecdote actually.

Also, to think that we could have gotten a fantasy RPG with deep worldbuilding instead of Doom.

And boy am I glad I get to live in the timeline with Doom.

[Lord Raziere]

And boy am I glad I get to live in the timeline with Doom.

I'm glad to live in a timeline with only one Doom, and lots of settings with deep worldbuilding, as Doom only works for what it is.

[Cespenar]

And boy am I glad I get to live in the timeline with Doom.

Eh, true, RPGs were dime a dozen and weren't looking for a savior in those days. Though on the other hand, Doom is such an "inevitable" game that it feels like someone would have made it no matter what, eventually.

[warty goblin]

Eh, true, RPGs were dime a dozen and weren't looking for a savior in those days. Though on the other hand, Doom is such an "inevitable" game that it feels like someone would have made it no matter what, eventually.

The FPS was probably inevitable (and also predates Doom). Doom itself is I think a pretty contingent piece of work; I'd go so far as to say a space marine shooting demons on Mars is downright idiosyncratic. Like, if you sat down and just thought about a game built around shooting things, you'd probably get something military or police or standard sci-fi themed. It's pretty easy to imagine a world where the something like that was the first FPS to gain major traction, instead of Doom's lurid fever dream of gore and speed. That reality looks a lot more boring to me, and probably wouldn't have produced Quake or Unreal or Duke Nukem. That also means no boomer shooter revival, no Doom remake, etc.

[The Glyphstone]

Any timeline without Chex Quest is automatically not the best timeline.

[Cespenar]

The FPS was probably inevitable (and also predates Doom). Doom itself is I think a pretty contingent piece of work; I'd go so far as to say a space marine shooting demons on Mars is downright idiosyncratic. Like, if you sat down and just thought about a game built around shooting things, you'd probably get something military or police or standard sci-fi themed. It's pretty easy to imagine a world where the something like that was the first FPS to gain major traction, instead of Doom's lurid fever dream of gore and speed. That reality looks a lot more boring to me, and probably wouldn't have produced Quake or Unreal or Duke Nukem. That also means no boomer shooter revival, no Doom remake, etc.

I don't know. If you look out of the games genre for a second, Evil Dead/Army of Darkness was a thing just before this, so flavor wise we were not that far off at that point in life. And for pacing, you can only go two ways if we dumb things down: methodical cover shooter, or run and gun. And all FPSs were closer to the second one by then anyway.

I know this is just what ifs + a lot of generalization, but what I mean to say is although Doom was just the right stuff at the right time, it's not necessarily "wow, how did they even come up with this stuff?" material. What they did was probably hastening the FPS timeline by a couple of years, give or take.

[Amechra]

it's not necessarily "wow, how did they even come up with this stuff?" material

I mean, it was on the technical side.

Carmack basically performed a technological miracle when he programmed Doom's engine.

[Cespenar]

I mean, it was on the technical side.

Carmack basically performed a technological miracle when he programmed Doom's engine.

Yeah, I know all that stuff, but we only know that since Doom made it in the first place. Who knows how many other faceless genius programmers solved similar stuff and furthered gaming tech in the 80s and 90s without us knowing it?

[Seppl]

Yeah, I know all that stuff, but we only know that since Doom made it in the first place. Who knows how many other faceless genius programmers solved similar stuff and furthered gaming tech in the 80s and 90s without us knowing it?

Probably not many, or even none. It's not like there is a bunch of unknown but revolutionary games lying around. Doom got famous because it was so technologically advanced. So, naturally people looked at what the developers behind Doom did and copied their ideas. Same with the other famous milestones of gaming. A surprising number of which were made by Carmac, so there is definitely a pattern of him regularly pushing the technological limits. In those times, games were not made by faceless cooperations with hundreds of programmers, you could actually know the people behind a game and ask them who exactly did what.

[The Glyphstone]

What was it again that made Doom a technical miracle? I want to say it was making a functional Z axis for level maps...

[Cespenar]

Probably not many, or even none. It's not like there is a bunch of unknown but revolutionary games lying around. Doom got famous because it was so technologically advanced.

Eh, those claims are even more outrageous and hard to substantiate than mine, so consider me out.

[GloatingSwine]

What was it again that made Doom a technical miracle? I want to say it was making a functional Z axis for level maps...

It was fiddlier than that.

It was the use of Binary Space Partitioning to speed up rendering and combining it with the z buffer to solve the visible surface determination problem (not drawing the back of polygon objects to the screen).

(Carmack used BSP on the SNES port of Wolf3D but just used raymarching to determine visible surfaces which was practical because Wolf3d is all orthogonal axis aligned walls)

Prior to Carmack digging into academic literature BSP was a technique for military flight sims not home computers.

[Seppl]

What was it again that made Doom a technical miracle? I want to say it was making a functional Z axis for level maps...

At the time 3D graphics were less about features and more about handling limitations. Computers at that time were unable to perfectly render arbitrary scenes (and in a way, they still are today…). 3D engines therefore were about imposing shortcuts to the render equations and using tricks to reduce the complexity of geometry computations. Also (though not yet relevant for Doom) to max out the huge parallel processing power of the upcoming 3D graphics cards. A good engine would find compromises and limitations that suit the intended gameplay, while still looking as realistic as possible. Or often, the other way around, the engine would dictate what kind of game could be made.

Therefore, the technological advancements of the Doom engine happen behind the scenes. It is about how it handles the level data, what restrictions it places on level design (or rather, which restrictions it removed compared to its predecessors), and how capable it is to render this on hardware less powerful than a modern TV remote. The average player would only note that they had never seen levels of this size and complexity. It even had stairs, movable elevators/platforms (though only up and down, not left and right. That is one of those limitations they had to use to speed up the calculations), and *gasp* corners that were not 90 degrees (I am not joking about this one)! That gave the engine a graphical fidelity that was unseen on that kind of hardware at the time (again, not joking).

Watch a gameplay video of Doom 1 and compare that to its predecessor Wolfenstein 3D. To modern eyes both look equally horrible, blocky and claustrophobic, but try to focus on the level geometry and its usage. The technological leap between the two will become obvious.

Also, the actual gameplay was really good, which certainly helped to make the game famous. They just had a really talented team, not only a talented engine developer.

Eh, those claims are even more outrageous and hard to substantiate than mine, so consider me out.

What? You think there are a bunch of hidden gems lying about? Some unknown genius who never achieved recognition? The list of games from those times that were good enough to find a publisher (and that is a very low bar) is short and exhaustive. There are certainly collectors in the world who have every game from this era in their collection. The revolutionary milestones and the people behind them are all known because people have seen and analyzed all these games. The chances that some kid, programming Basic in their room after school, stumbled upon some genius solution to an unsolved problem and never realized it or published it, is non-existent. When a game did some impressive new thing (for example the z-axis in Doom levels) people would notice immediately and wonder how it worked.

You do not even need a place in the spotlight to be recognized. Games using the Voxel Space engine (early 1990s, same era as Doom) had only moderate success. Still, people recognized that there was genius behind this completely different approach to 3D graphics that was better suited to a completely different kind of gameplay than Doom. Historically, the technology did not quite work out, but it is still recognized as revolutionary.

[Spore]

The Elder Scrolls is exactly that and was based on the developpers' D&D campaign (originally).

I ****ING KNEW IT!

Ahem...I mean, I did not know that until recently, but the whole world has a very "white space is everywhere where the DM/writers didn't go to yet"-vibe to it.

[Radar]

Doom can and should be seen as a technological wonder of it's time, but it's handling of 3D was still very simplistic and restricted. Yet, just two years later we got Descent with seemingly unconstrained 3D design of levels, full 3D graphic enemies and a pretty good handling of light sources (further developed in the sequel released just a year later*). I never dug into the details, but it would be interesting to see how the innovations in the Doom engine helped make the next big step.

*For example, every shot of an energy weapon was also considered as a source of light of a proper color (so sending a barrage of red laser shots would make all the surrounding walls reddish depending on the other light sources in the area) and in the dark you actually could light up the place like that or shoot an actual flare.

[GloatingSwine]

Doom can and should be seen as a technological wonder of it's time, but it's handling of 3D was still very simplistic and restricted. Yet, just two years later we got Descent with seemingly unconstrained 3D design of levels, full 3D graphic enemies and a pretty good handling of light sources (further developed in the sequel released just a year later*). I never dug into the details, but it would be interesting to see how the innovations in the Doom engine helped make the next big step.

*For example, every shot of an energy weapon was also considered as a source of light of a proper color (so sending a barrage of red laser shots would make all the surrounding walls reddish depending on the other light sources in the area) and in the dark you actually could light up the place like that or shoot an actual flare.

Descent had dynamic light sources, but coloured light sourcing didn't arrive in the series until Descent 3 in 1999, I'm pretty sure the first game with coloured light sources (and transparency) was Quake 2, and they needed a 3d accelerator card.

Descent's levels weren't much more geometrically complex than Doom's, but it did have 6 degrees of freedom which meant that the layouts could twist in different directions.

System Shock did have object complexity doom didn't though. It didn't have as much freedom to have arbitrary surfaces (I'm pretty sure it uses a fixed tile size to build the world because it's based on the Ultima Underworld engine) but it did have suspended 3d platforms which you could walk under, which the Doom engine was not capable of.

[Radar]

Descent had dynamic light sources, but coloured light sourcing didn't arrive in the series until Descent 3 in 1999, I'm pretty sure the first game with coloured light sources (and transparency) was Quake 2, and they needed a 3d accelerator card.

Not sure how they faked those colour effects in that case, as you can see from gameplay videos of Descent 2 that shooting lasers did light the surrounding area up in red, violet, green etc.

Descent's levels weren't much more geometrically complex than Doom's, but it did have 6 degrees of freedom which meant that the layouts could twist in different directions.

They were full 3D though - not 2D with some height differences. Tight corridors had rectangular cross-sections, but they could twist and turn quite freely. Larger areas had rather arbitrary geometry. They very visibly tried to use as few vertices as possible to get the desired shapes but this seemed to be more of a computational limitation rather than engine limitation.