Good old Doom 2 -- bugs or mistakes?

So, yeah, playing through the old Doom 2. Noticed the lights weren't aligned properly in the new secret area on Map31. Only reason this is worth noting is since the textures weren't aligned right, there is no light source to make the bright lights in that room where you get the bfg and four backpacks. Sort of a blatant mistake on id's part. I never noticed it before tho--but I looked closely at those bricks and you can see they have lights on them but just weren't aligned on the x-offset properly.

Any other bugs anyone knows from Doom 2? Version 1.9 that is.

More like Sandy Petersen's the grandaddy of DOOM speedmapping.

I also just found a missing upper texture where two platforms raise by two switches incrementally on map19 The Citadel. Just a small one, tho.

The only true bug I remember off the top of my head is the one in Map06. If you try "use" on a door track texture the of the red keyed door that leads outside to where you find the Hell knight, Doom crashes, because the linedefs are type 117 with a tag of 0.

Don't forget Map05. The secret area behind the exit accidently has a sector tag of 9 rather than a sector type of 9.

This means if you press the switch elsewhere on the map with a tag of 9 (one of the doors in the area with the Blue Armour), you break said secret area and are unable to access it.

Several port's including ZDoom fix this one though.

myk said:

The only true bug I remember off the top of my head is the one in Map06. If you try "use" on a door track texture the of the red keyed door that leads outside to where you find the Hell knight, Doom crashes, because the linedefs are type 117 with a tag of 0.

Holy shit - just tried it... unbelievable.
Interesting!

I remember a different one on map28. The pits in the room with the red door (that rise when you get the sphere) don't have monsters in them in the lower skills. If you fall in, you're screwed. :)

If there was a way to raise them from inside, then it would be fine... you just sit there and can't get out.

Hellbent said:

I never noticed it before tho--but I looked closely at those bricks and you can see they have lights on them but just weren't aligned on the x-offset properly.

If that's your definition of "bug", I doubt the forum would be able to hold a list of all the bugs in Doom 2.

The rest of the ones listed so far seem like simple design mistakes, so I'll add the impossibility of getting 100% secrets on map15 due to mistagging secret sectors. Ignoring ugly aesthetics, I think that about covers it.

Vile said:

I remember a different one on map28. The pits in the room with the red door (that rise when you get the sphere) don't have monsters in them in the lower skills. If you fall in, you're screwed. :)

If there was a way to raise them from inside, then it would be fine... you just sit there and can't get out.

Heh, I remember practicing that map from scratch on a lower skill level and getting stuck in the mancubus one as I was about to finish the map. I think I was making a demo for somebody too.

Vile said:

The pits in the room with the red door (that rise when you get the sphere) don't have monsters in them in the lower skills. If you fall in, you're screwed. :)

Or on UV if you decide to kill them safely using rocket splash damage. And then drop down into the pits, assuming there will be a power-up and a switch. I'm pretty sure I did that years ago.

In terms of bugs, I guess you could call the sergeant stuck in a wall in map02 a bug (note that I am not referring to the sleeping sergeant, which is much more an engine bug than a map bug). This was introduced in 1.9 - it was not there in 1.666. In fact, map02 was changed in 1.9 in a number of other small ways that aren't readily explicable. A likely spechits overflow (the only one in the Doom2 iwad) was removed in the process though.

The empty secret in map 25 has always been a favourite of mine. :-)
(There's a BFG on skills 1-3 and some cells in multiplayer, but on UV and NM it's completely empty)

I remembered a few from 30nm/30uv sessions...

The final sector in map07 raising itself more than once after killing the final spiders simultaneously. If it raises itself twice, the map can still be finished by running off the edge of the mancubus platform, but it's still annoying... however, there was one or two occurrences where it raised itself THREE times, which can only lead one to start over again. Ugh.

On map20, that teleport that leads to a lowering elevator to the zombie room... it's possible to teleport without activating the elevator, trapping you. I know many who have experienced this one. :)

How about monsters cemented together... Frex, Caco and Spectre stuck together on map 18 in the BFG room at Skills 1 and 2; And Demons stuck together on map 31 at Skills 4 and 5.

Vanilla v1.9 demos of these, the blind map-02 Sergeant, and the map 07 stair-step bug can be found on the OddDemos page.

As for weird visuals: One I remember is on map 21, Nirvana. In the southwest corner of the map, activate the 4 switches and then the nearby barrier/lift. Ride up and walk a few paces east, up to the top of the steps. Turn back around to look west, and strafe right all the way to the north, and back, while looking west the whole time, and you should see an unusual effect in the ceiling.

Well, I'll be ... you can even see it when you're going for the rocket launcher! I never noticed that!

Ledmeister said:

As for weird visuals: One I remember is on map 21, Nirvana. In the southwest corner of the map, activate the 4 switches and then the nearby barrier/lift. Ride up and walk a few paces east, up to the top of the steps. Turn back around to look west, and strafe right all the way to the north, and back, while looking west the whole time, and you should see an unusual effect in the ceiling.

This can be easily seen in a source port too, particularly something like the latest version of GZDoom. Go into that room and just look straight up.

In map 01 of doom 2, the secret in the duel switch platform can still be accessed after the platform has lowered by pressing the use key on the linedef. Classic.

skadoomer said:

In map 01 of doom 2, the secret in the duel switch platform can still be accessed after the platform has lowered by pressing the use key on the linedef. Classic.

I frequently take advantage of this one, so much so that I've stopped noticing it.

I've stopped really noticing some as well, since they've been standard parts of speedruns... like map21's blue doors being worthless. :)

Ledmeister said:

As for weird visuals: One I remember is on map 21, Nirvana. In the southwest corner of the map, activate the 4 switches and then the nearby barrier/lift. Ride up and walk a few paces east, up to the top of the steps. Turn back around to look west, and strafe right all the way to the north, and back, while looking west the whole time, and you should see an unusual effect in the ceiling.

Looking at the level in Doom Builder, I notice linedefs 114 and 134 don't reference sector 49 on their front sides, rendering it unclosed. Instead, they reference sector 50 -- which consists only of those linedefs. As the result of sector 49 being unclosed, the light levels and ceiling flats of sector 51 and sector 54 end up bleeding to the top of the screen on the front sides of those linedefs.

Very weird... I didn't even notice that until I read your post! Nice find!

skadoomer said:

In map 01 of doom 2, the secret in the duel switch platform can still be accessed after the platform has lowered by pressing the use key on the linedef. Classic.

That's not a map bug, it's a Doom limitation. There is a worse situation, as in odyssey.wad MAP02, where a hidden switch, which is to be revealed later, is an exit.

There's a "pistol only" map in Eternal which can be exited in a few seconds flat if you know where one of those switches-in-the-floor is hidden in advance. It's in the room you start in, and although it releases a Cyberdemon as well as opening the exit, it is quite simple to reach the exit without getting blown up :P

Of course this strands you in the next level with no weapons, so it's only a good idea for a raw speedrun I guess :)

You guys are pretty much derailing this by adding addon levels.

printz said:
That's not a map bug, it's a Doom limitation.

It's definitely a bug of that sort, since ignoring an engine limitation is one of the main ways you can produce a map specific bug, as opposed to an engine specific (or a general) bug*.

And then there's the 32 unit openings, that the Player can glide through, such as at the end of Map16, or through the torches outside in Map19. Not to mention numerous item or key grabs by bumping. These probably weren't evident during development, though.

* Such as being able to run over any linedef without triggering it.

myk said:

It's definitely a bug of that sort, since ignoring an engine limitation is one of the main ways you can produce a map specific bug, as opposed to an engine specific (or a general) bug*.

Maybe they ignored it intentionally or out of laziness, knowing what would happen but asking who gives a crap. In that case it would be an imperfection, a "bug", but no mistake here, finally realizing the title of this thread, "bugs or mistakes", thus making difference between the terms.

EDIT: excessive deletion spree detected. Am I really such a troll? :|

Yeah, that map21 visual bug sticks out like a sore thumb nowadays... speaking of which, I remember another bug in the same room. Hit two of the switches, then hit the last two as fast as you can. The stairs won't build properly and you'll be trapped. If you hit the first two switches this fast, it'll actually correct itself if you hit the next two switches normally. Ironically enough, the only way to beat this bug is to use another... finish the level using the yellow bar glide.

Obviously that "press a switch that's actually physically higher or lower than the player" bug is useful in E1M3. Where there's that big O with acid surrounding it and inside it, just press the switch there without falling in the hole and the acid is neutralized >:)

more useful to exit e2m2

Those are pretty well known. The reason they haven't been mentioned is that they're in DOOM (not DOOM II).

Vile said:
Hit two of the switches, then hit the last two as fast as you can. The stairs won't build properly and you'll be trapped. If you hit the first two switches this fast, it'll actually correct itself if you hit the next two switches normally.

I've never managed that one. Do you know if any demo displays it?

I'll throw together a demo real quick... one minute.

EDIT: http://www.sendspace.com/file/0dc0ov

Recorded in vanilla doom... I replicated it in gzdoom as well.

Vile said:
http://www.sendspace.com/file/0dc0ov

Cool, thanks!

That map 21 bug is a map error. Sector 50 is "wrong". The front side of lines 114 and 134 should have referenced sector 49.

Here are a bunch of similar errors I'm aware of ...

Map 2 - Lines 327/328 floor. Line 491.

Map 14 - Lines 429\430.

Map 18 - Lines 451/459.

Map 19 - Line 636.

Map 22 - Sectors 124, 130 and 133.

Map 28 - Ceiling of sector 0 where lines 105/106 etc are.

Map 30 - Line 13.

myk said:

Cool, thanks!

No problem. Finding an existing demo for this would be difficult anyway since that bug kills any runs it appears in. I'm sure the origin of that is hitting the buttons faster while attempting movie runs again... funny, it seems like there were many bugs that only appeared when playing as fast as possible, which is contrary to the more careful approach of playtesting. A practical use for speedruns. ;)