Monsters vs. Same Monsters

[Seiat]

We all know that when a doom monster hits one that isn't the same as himself (except for some), the other monster will turn around and fight it regardless of whether it's a zombieman or a cyberdemon. I find it amusing, personally.

But on a few occasions i got monsters that wouldn't normally fight each other to fight each other. In the first level of Inferno, I don't remember how but i got two demons to fight each other. It was funny cuz the dumb things ran up and down next to each other and were too stupid to bite each other.

On another occasion on the level Barrels o' fun, when you go through the first teleporter and there's a bunch of hell knights, I shot one pistol shot then ran and a hell knight blew the barrels up, then when I went back the other hell knights were trying to kill it. When he got close enough for them to scratch it they killed him lol.

The most unique one was on a custom made level on a CD called 'Doom 2 Explosion' with a whole bunch of wads, an arch vile killed me while i was beside a barrel, which then blew up and hurt another arch vile. Then that arch vile killed the other arch vile. Confusingly amusing, eh?

Anyone else have any experiences of this kind?

[myk]

Yeah, barrel damage can cause intraspecies infighting.

You might want to try Espi's Barons o' fun.

I'm skeptical in regard to what you're saying about the Archvile though... because they have a special characteristic where they don't get attacked by anything. Are you sure it killed it on purpose? Because the splash damage of their attack can hurt other Archviles, and even themselves.

[Shadow Dweller]

in zdoom, you can do this by opening the console and typing in "summonfriend <monster of choice>" and "summon <same monster of choice>"

try getting two cyberdemons to fight

[Vegeta]

This doesn't work in vanilla DOOM (except in the first versions).

In the other hand, in vanilla Hexen you can make a monster fight against himself by leading it to burn a tree close to it. After receiving some damage from the fire it start biting himself. The kind of situations where a Hexen fan prefer to close his eyes in shame, or restart/change the map as fast as posible ;-)

[Grazza]

Vegeta said:

This doesn't work in vanilla DOOM (except in the first versions).

Yes it does, as I imagine you'll realize if you reread the initial post.

What you're referring to, I imagine, is that in Doom version 1.2 or earlier, a monster would attack itself if it exploded a barrel that caused itself damage. But that isn't what the initial post is referring to.

One odd quirk that is perhaps less known: if Monster A hits a barrel but doesn't explode it, then if something else (e.g. the player) then causes that barrel to explode, harming Monster B (of the same type as Monster A), then Monster B may retaliate against Monster A. Why it should attack Monster A rather than the player, I'm not entirely sure, but this does happen (there are demos illustrating it).

Archie splash damage does harm anything within range that can be hurt by splash damage. This includes themselves and other arch-viles, but doesn't mean that they were actually targeting them. One way to kill an arch-vile without using any ammo is just to stand right next to it, and let it attack you. Obviously you'll need an invul for this to be a practical proposition, though you can also use it together with weapon attacks (I found this useful on ksutra map15, for instance).

That's also why it is useful to get a cyber to hit an archie. You can then leave the area, and the archie will repeatedly attack the cyber, doing damage to the pair of them (blast damage to the cyber, splash damage to the archie). You can later return, generally to find a weakened cyber and a dead archie.

[Ichor]

Vegeta said:

This doesn't work in vanilla DOOM (except in the first versions).

In the other hand, in vanilla Hexen you can make a monster fight against himself by leading it to burn a tree close to it. After receiving some damage from the fire it start biting himself. The kind of situations where a Hexen fan prefer to close his eyes in shame, or restart/change the map as fast as posible ;-)

Many times I'd just put that monster out of it's misery. Most of the time though, I've already burnt up all the trees just because it's fun watching them burst into flames like that, and to get them out of the way

[myk]

Grazza said:
One odd quirk that is perhaps less known: if Monster A hits a barrel but doesn't explode it, then if something else (e.g. the player) then causes that barrel to explode, harming Monster B (of the same type as Monster A), then Monster B may retaliate against Monster A. Why it should attack Monster A rather than the player, I'm not entirely sure, but this does happen (there are demos illustrating it).

Sometimes monsters get hit but ignore that attack and continue to attack whatever they were after (it's common to see this in Cooperative, but also when infighting goes on).

I'm guessing this property is in its way applied through Barrels as well, so since the monster got hold of the Barrel ("owns" it), and the Player who destroyed it didn't, it is counted as the monster's possession when it finally hurts the other monster.

I think it can also happen that monster A could blow up a Barrel by monster B, and monster B might ignore monster A as if nothing had happened.

You can also similarily sometimes shoot a "dormant" monster that hasn't seen you and it will not react. Generally targets only ignore smaller amounts of damage, and easily get angry when they are hurt a lot.

[Inferno]

Grazza said:

That's also why it is useful to get a cyber to hit an archie. You can then leave the area, and the archie will repeatedly attack the cyber, doing damage to the pair of them (blast damage to the cyber, splash damage to the archie). You can later return, generally to find a weakened cyber and a dead archie.

I've done this before, although it's very risky. The two places that come to mind are Doom2's map 20 and Plutonia's map 32. Also, unless you get a few archies to attack one cyberdemon, the killing process takes a little while, mostly since the arch-vile's attack has significant lag time.

[printz]

Alien Vendetta MAP17 is now my classic show for clashing Arch-viles into the Cyberdemon ;)

myk said:

Sometimes monsters get hit but ignore that attack and continue to attack whatever they were after (it's common to see this in Cooperative, but also when infighting goes on).

I think this is time-based, i.e., you have to wait a few seconds during which the monsters shouldn't be hit by its current target, until your shots make you target. It's something about a treshold (I'm not sure).

myk said:

I'm guessing this property is in its way applied through Barrels as well, so since the monster got hold of the Barrel ("owns" it), and the Player who destroyed it didn't, it is counted as the monster's possession when it finally hurts the other monster.

Maybe it's true, it's plausible and scientifically possible, but this format didn't work on me:

/---\
|v v|         v=monster
| B |         B=barrel
|   |         ^=player
| ^ |
\---/

You see, a monster is supposed to (and does) hit the barrel, thus "remotely" hurting the other. Why don't they fight each other this way? Does the shooting monster have to be farther away from the barrel? Do I have to be away from their sight when the barrel blows up? Am I badly wrong? I tested it on Doom95, which has to be quite close to Doom.exe.

myk said:

I think it can also happen that monster A could blow up a Barrel by monster B, and monster B might ignore monster A as if nothing had happened.

Same as the first point.

myk said:

You can also similarily sometimes shoot a "dormant" monster that hasn't seen you and it will not react. Generally targets only ignore smaller amounts of damage, and easily get angry when they are hurt a lot.

I don't think so. Even a tough BFG can't change a spiderdemon's plans of perforating his cacodemon. But pistolling a spiderdemon whose target has been in hiding works for becoming acquired.

[Graf Zahl]

myk said:

You can also similarily sometimes shoot a "dormant" monster that hasn't seen you and it will not react. Generally targets only ignore smaller amounts of damage, and easily get angry when they are hurt a lot.

I don't know where you get that idea but it's definitely wrong. It may appear this way because the shotguns fire 7 or 20 hitscans and inflict damage more than once. But for each single damaging the actual damage amount doesn't matter at all.

This is the entire target switching code from the original Doom source release and there's nothing in there that checks the amount of damage:

    if ( (!target->threshold || target->type == MT_VILE)
	 && source && source != target
	 && source->type != MT_VILE)
    {
	// if not intent on another player,
	// chase after this one
	target->target = source;
	target->threshold = BASETHRESHOLD;
	if (target->state == &states[target->info->spawnstate]
	    && target->info->seestate != S_NULL)
	    P_SetMobjState (target, target->info->seestate);
    }

The only interesting thing in there is the incorrect check for the spawn state which will skip changing the state if the monster happens to be in anything but the first frame of its idle animation.

[myk]

Graf Zahl said:
I don't know where you get that idea but it's definitely wrong.

Heh, since I was aware that using a Rocket or a Pistol shot is the same (as opposed to using a Shotgun/SSG, a stream of Chaingun/Plasma shots, or a BFG blast), it's more like it was pertinent to clarify that the amount is in hits, not in hit points, like you graciously pointed out. Momma said I didn't need to go into detail about everything to be "right" (I'd get too anal if I did, anyway).

I was hoping a code savvy person would make further clarifications in one way or another, anyhow.

The only interesting thing in there is the incorrect check for the spawn state which will skip changing the state if the monster happens to be in anything but the first frame of its idle animation.

As far as I remember the monster ignoring me has happened in occasions where I was creeping toward a monster, barely seeing it around a corner or through a window in another room from where it couldn't see me. I'd shoot it (with the Pistol) and see the blood splat, but it would just stand there. Here's a demo of the phenomenon (DOOM II v1.9).

[Raikoh_Minamoto]

Seiat wrote:
But on a few occasions i got monsters that wouldn't normally fight each other to fight each other. In the first level of Inferno, I don't remember how but i got two demons to fight each other. It was funny cuz the dumb things ran up and down next to each other and were too stupid to bite each other.

Monsters of the same species aren't hurt by each other's ranged attacks. Melee attacks will damage anything and everything-- Demons specialize in it.

I noticed that this didn't continue in Doom 3, because I've gotten Imps to kill each other with their fireballs. But, I've also had an Archie as a meatshield, and he kept taking Imp fireballs like there was no tomorrow, yet he never attacked them. Maybe it didn't do damage (because the Archie revels in heat?), or maybe the amount of damage was too trivial for it to care.

On another Archie-related side note, I've seen that the Arch-Vile's demand that others respect its authority (read: other monsters won't attack it) continued in Doom 3. This one tentacle zombie guy must've hit that Archie while he was "winding up for the pitch", and the Archie just started brutally kicking its ass, but the poor tentacled bastard kept coming for me, totally ignoring the fact that he was being pwned by his comrade.

[jobro]

Heh lol that was kinda funny. I have to disagree about ranged attacks. Put a cyberdemon against a mastermind (doom 2 map 20) Rush up the stairs and make sure the mastermind sees you, then head back down and let the mastermind and the cyber do their buisness.

[Terra-jin]

Grazza said:

One odd quirk that is perhaps less known: if Monster A hits a barrel but doesn't explode it, then if something else (e.g. the player) then causes that barrel to explode, harming Monster B (of the same type as Monster A), then Monster B may retaliate against Monster A. Why it should attack Monster A rather than the player, I'm not entirely sure, but this does happen (there are demos illustrating it).

I think this is because the barrels can also target monsters. When monster A hits the barrel, it targets monster A and keeps its target when the player finishes it off. Then, the explosion damage is attributed to the barrel's target - Monster A.

Graf Zahl said:

I don't know where you get that idea but it's definitely wrong. It may appear this way because the shotguns fire 7 or 20 hitscans and inflict damage more than once. But for each single damaging the actual damage amount doesn't matter at all.

From what I've seen in ZDoom, a dormant monster (tested with notarget) always reacts when it enters the pain state, and not always when it doesn't enter that state.

[981178]

yeah i tried that in command in gzdoom. it's funny seeing to arachnotron's go at it, or 2 spider mastermind's.

[BoldEnglishman]

Seen as this thread is bumped anyway --> 2 Spider Mastermind's will fight each other anyway if they hit one another because it is a hitscan attack (the last level of some megawad had 2 SM's at the beginning which you could manipulate into killing each other).

Also, jobro -- read what he said. Monsters of the SAME species' ranged attacks don't hurt them directly, not different species.