Stealth mods?

[Sqrrt121]

Hello I would like to know if there are any stealth doom mods out there or if it is possible. Thanks!

[Patrol1985]

I doubt it, because stealth games are usually based around the idea of enemies roaming corridors in prearranged patterns which you can abuse to sneak through.

Doom does not have roaming monsters - they just stand in place until they notice you or are otherwise alarmed (gunshots, etc.). Therefore, those monsters are usually positioned in such a way to make it impossible not to be noticed.

Then again, so many Doom mods have appeared over the years that I may be missing something.

[Gez]

The engine is definitely not geared for stealth gameplay:
1. If noise is made in a sector, that sector is permanently "active".
2. Monsters, once woken up, never fall asleep again.
3. Monster line of sight is not hampered by light level.
4. Monster FOV is 180° when asleep, 360° once woken up by sound.
5. Invisibility throws off monster aim, but not their sight.

Rather than stealth, I could see some sort of puzzle-oriented gameplay where you need to activate switches to close doors, etc. so that monsters lose line of sight to areas you need to go through.

[TwinBeast]

I made monsters walk around randomly in some old mod I was doing for Doomsday. They would also randomly stop moving when they had lost sight of player, and continue moving after a while.

But I didn't include any stealth avoidance of them. I just did it so they don't run around all the time when they've seen player.

[Dexiaz]

Gez said:

2. Monsters, once woken up, never fall asleep again.

Not true. There are few mods where are monsters can back into "waiting" mode.

But anyway, Doom engine isn't good for stealth mods.

[Maes]

Gez said:

2. Monsters, once woken up, never fall asleep again.

Not true, even in vanilla Doom. If a monster is persuaded to change target due to infighting and its new target dies, the monster "forgets" the first target and just idles, unless it's provoked again by another hit, or by seeing the player.

Lost Souls, while this might not seem to be the case, technically "fall asleep" after each attack they deliver, as they only retaliate once against an attack with a tit-per-tat tactic. However, with the player in view, they constantly wake up again, so this is not immediately obvious.

[Tristan]

Also 3 and 5 on Gez's list can be worked around in ZDoom I think.

[Jayextee]

I did a stealth map for Nex Credo. It was little other than "don't wake the Cyberdemons", but made for a nice enough change of pace.

The engine is pretty limited for it, although that doesn't mean you can't get creative.

[wesleyjohnson]

DoomLegacy has a provision for monsters to walk patrol paths.
Have not tried it myself and do not know of any wads using it to demonstrate it, so how well it works (if at all anymore) is unknown at the moment.

Try Twilight for DoomLegacy. It is a little along those lines, but not a whole lot. Has covert action, sniper, hostage rescue, etc..
Yes, it has hostages which MUST NOT BE KILLED.
The training session can be the hardest part to get through.
There were recent fixes in DoomLegacy alpha4 to fix bugs in Twilight.
http://doomlegacy.sourceforge.net/
http://www.doomworld.com/events/twilight/interview.shtml

[Shadow Hog]

It seems like something that'd be more applicable to a ZDoom mod than anything else, since at least there you can set up patrol routes for enemies, and possibly DECORATE in some highly rudimentary AI (I dunno, something like "if monster can no longer see target, place a marker where target was last seen and have the monster head that way; if that marker is reached and the target still can't be found, then the target has successfully run away, and monster should attempt to return to its patrol route").

I've even had a good setup for such a mod in my head for a while. Say, you are the sole survivor of an invasion from Hell, much like Doom... except unlike Doom, UAC kicked Hell's ass, and Hell was your side of the war. You, a zombieman with only a pistol and practically no armor, have to evade patrols of UAC marines armed with high-end weaponry like SSGs, rocket launchers and BFGs and make your way to the portal back to Hell intact. Attempting a head-on confrontation would be suicide, as their weaponry would tear you to shreds while your weapon would barely put a dent in their armor...

[Maes]

Gez said:

Rather than stealth, I could see some sort of puzzle-oriented gameplay where you need to activate switches to close doors, etc. so that monsters lose line of sight to areas you need to go through.

There was a certain map where you had to do just that -it was all about getting around without alerting any of the archviles in a map.

There were zones where shooting was allowed, and others (marked by an "evil eye" decoration) where shooting would release ALL archviles in the map at once right in your position, meaning certain Doom (pardon the pun).

You had to solve puzzles to activate switches that blocked those areas, revealed alternate routes or or otherwise neutralized the evil eye in a certain zone. Innovative, if nerve-wracking.

[Foxpup]

Maes said:

Not true, even in vanilla Doom. If a monster is persuaded to change target due to infighting and its new target dies, the monster "forgets" the first target and just idles, unless it's provoked again by another hit, or by seeing the player.

Lost Souls, while this might not seem to be the case, technically "fall asleep" after each attack they deliver, as they only retaliate once against an attack with a tit-per-tat tactic. However, with the player in view, they constantly wake up again, so this is not immediately obvious.

That's not entirely true either. Due to a bug in the way monsters hear sounds, if a monster falls asleep in a sector in which the player has previously made a sound, it will immediately re-awaken and target the player if he is alive. This behaviour can easily be confirmed with lost souls: if you don't make any noise and let a lost soul see and attack you (and dodge the attack), it will fly into a wall and fall asleep, and it won't wake up since it can't see you when it's facing the wall. But if you previously made a sound in the sector, it will re-awaken after it hits the wall, even though it can't see you.

[joepallai]

Didn't Enjay make a zdoom level inspired by Thief?

[Doominator2]

Dont know of any stealth mods for the original doom but there is the Thief inspired doom 3 mod called the dark mod.

[TheMightyHeracross]

wesleyjohnson said:

DoomLegacy has a provision for monsters to walk patrol paths.
Have not tried it myself and do not know of any wads using it to demonstrate it, so how well it works (if at all anymore) is unknown at the moment.

Try Twilight for DoomLegacy. It is a little along those lines, but not a whole lot. Has covert action, sniper, hostage rescue, etc..
Yes, it has hostages which MUST NOT BE KILLED.
The training session can be the hardest part to get through.
There were recent fixes in DoomLegacy alpha4 to fix bugs in Twilight.
http://doomlegacy.sourceforge.net/
http://www.doomworld.com/events/twilight/interview.shtml

That's a Legacy mod? Works on ZDoom for me. I thought it was for Boom-compatible ports...

[joe-ilya]

Deathmatch sometimes requires stealth if you want to kill a BFG spammer.

[wesleyjohnson]

Twilight Warrior was developed for Doom Legacy. It uses Legacy transparent water.
ZDoom is reported to work too, except for a minor problem on Map08.
This is likely due to not using many of the more unique DoomLegacy linedefs. I do not remember it using any 3d floors.

[Waffenak]

Stealth doesnt suit doom very well

[Xaser]

Gez said:

The engine is definitely not geared for stealth gameplay:
1. If noise is made in a sector, that sector is permanently "active".
2. Monsters, once woken up, never fall asleep again.
3. Monster line of sight is not hampered by light level.
4. Monster FOV is 180° when asleep, 360° once woken up by sound.
5. Invisibility throws off monster aim, but not their sight.

I find this post rather puzzling, as there's no mention of the fact that ZDoom can do 1, 2, and 4 (and somewhat 5, though it's not customizable currently). You make it sound like it's completely impossible. :P

The more pertinent issue really is the fact that nobody (that I know of) has made a serious effort to try it, though of course it wouldn't be easy. The lack of light level as a stealth factor is most certainly a big issue for folks wanting to make something Thief-like, though, so something about that would have to be specially-coded by someone in a ZDoom fork to make it happen in that fashion. Barring light, the tools are in place to do this to some sort of extent.

Now that I think about it, if there was some kind of feature in place to retrieve the light level of the sector an actor is standing in, one might be able to fill in the gaps with ACS. Lots and lots of it, of course. May be best to WFDS either way. :P

[Jayextee]

Isn't player visibility to monsters affected with some kind of sector trickery? I remember self-referencing sectors messing with this a little.

[Quasar]

Strife tried, but its main fault was in only allowing stealth in mostly the places the designers specifically wanted you to be able to exploit it (mainly, in town areas, the Power Station, the Badlands, and the Oracle's Temple). Everywhere else pretty much they eventually force you to "blow your cover" somehow, either with robots that always recognize you as a foe and even if dispatched with your bare hands, set off the alarm anyway when they explode - or by spamming alarm lines everywhere, sometimes invisible ones at that which have no real reason for existing.

They were sort of schizophrenic about it, really. Is stealth supposed to be a factor, or not? Why should there be levels with Blackbird telling me at the get go that "it looks like stealth is out!" - why not give me the opportunity of figuring out a way to do stealth there instead of forcing tons of tiring combat?

It was a lost opportunity. I think it could be done better, but probably would require native code modifications, or some heavy extensions to ACS and DECORATE over what are already available if you're doing it in ZDoom.

In fact, I think doing it explicitly as a Strife sequel would be awesome. Make it more like Thief where you certainly can do some killing and fighting, but it's best avoided most of the time.

[Gez]

Xaser said:

I find this post rather puzzling, as there's no mention of the fact that ZDoom can do 1, 2, and 4 (and somewhat 5, though it's not customizable currently).

So when on Doomworld I don't always assume people are looking for ZDoom-specific answers, sue me. :p

Yeah, with advanced ports which set out to add plenty of shiny new modding features, the possibilities are greatly increased.

But it's still kind of using said modding features to fight against the underlying engine architecture (viz. original Doom engine) rather than using them to enhance the game. You can do it, but there's plenty of hoops to jump through, and the result will still be kinda subpar compared to a game that was designed from the ground up with stealth mechanisms in mind.

[Shadow Hog]

I'm also not entirely sure how you'd have a guard return to his patrol once his target is considered "lost", without making the level design extremely basic, since Doom's pathfinding is... well, perfunctory, at best, last I checked.

[Foxpup]

Jayextee said:

Isn't player visibility to monsters affected with some kind of sector trickery? I remember self-referencing sectors messing with this a little.

I don't think so. Perhaps some REJECT builders get confused by self-referencing sectors? That's the only thing that might affect it.