Swarms--a good mechanic?

[Elder-Basilisk]

I've been reviewing the 3.5 SRD and I rather like the addition of swarms to the game. They seem like a very good way to make a creeping doom (or a creeping hellish bloodwasp doom as the case may be) an intersting encounter.

However, there are some things that just seem off about the way they interact with magic--for instance a centipede swarm that walks through a wall of fire is likely to survive. . . and a character with fire shield active is not immune to a swarm--that seems like the kind of thing that ought to deal massive damage to any swarm in the vicinity and keep the swarm from damaging the creature at all but it doesn't. In fact, since it technically effects only a single attacking creature rather than an area, a swarm is arguably immune to fire shield. The same is true of Flaming Sphere. It seems like that should be particularly effective against swarms but in fact, it's almost completely ineffective. And then there's the fact that, practically the only thing swarms are vulnerable to is area effect magic (not too much of a problem although it does further shift the 3.5 "options" toward "every wizard must cast fireball") yet all swarms seem to have good reflex saves--very good in most cases (The CR 8 Hellwasp swarm is at +14 for instance--and the maximum DC any 8th level wizard is likely to have is DC 22 (18 int +2 level+2 headband, greater spell focus, 4th level spell)). And since swarms attack by occupying their victims squares and high CR swarms tend to have good movement, the area effects are almost certain to catch PCs as well as the swarm. Does anyone else see this as problematic? (And if so, has anyone come up with good ways to get around it (either in the rules or as house-rules; I can come up with ad-hoc solutions myself but I'd rather avoid that)).

Also, there's no template for taking a tiny creature and turning it into a swarm. (I would love to spring a stirge swarm on PCs at some point. . . that would also be somewhat less likely unbalanced an encounter since as a swarm of tiny rather than fine creatures it wouldn't be immune to weapon damage--although then one might say that cleave doesn't work properly (I'd be tempted to say that cleave gives a free attack on any hit against a swarm of tiny creatures).

 

[Knight Otu]

I was about to type that swarms suffer a -10 penalty to some saves, but checked the SRD first. Good that I did, because they instead suffer "half again as much damage (+50%) from spells or effects that affect an area". At least this means that a successful save for half deals normal damage (Thanks to DnD math: 1 -0.5 +0.5, if I remember the rule correctly). In general, I think swarms are too invulnerable for their CR, especially since most fighter-types will have a hard time to contribute (maybe they should suffer half damage from bludgeoning weapons?).

Well, other than the fact that they are a bit too invulnerable, and that they do not easily work with templates, I like the swarm rules very much.

Also, there's no template for taking a tiny creature and turning it into a swarm.

I have the sneaky suspicion that this is because such a template would be very hard to balance - White Wyrmling Swarm, anyone?

 

[Someone]

However, there are some things that just seem off about the way they interact with magic--for instance a centipede swarm that walks through a wall of fire is likely to survive. . . and a character with fire shield active is not immune to a swarm--that seems like the kind of thing that ought to deal massive damage to any swarm in the vicinity and keep the swarm from damaging the creature at all but it doesn't. In fact, since it technically effects only a single attacking creature rather than an area, a swarm is arguably immune to fire shield. The same is true of Flaming Sphere.

Since torches and energy (flaming, etc) weapons do affect swarms, you can easily rule that this is a similar situation.

 

[Nail]

.... a swarm is arguably immune to fire shield.

Are you sure?

Fire Shield excerpt:
Any creature striking you with its body or a handheld weapon deals normal damage, but at the same time the attacker takes 1d6 points of damage +1 point per caster level (maximum +15).

excerpt from Swarm entry:
For game purposes a swarm is defined as a single creature with
a space of 10 feet....

A weapon with a special ability such as flaming or frost deals its full energy damage with each hit, even if the weapon’s
normal damage can’t affect the swarm......

Moreover, the swarm does have an "attack" listed. So it should take damage each time it attacks, as per Fire Shield.

It is pretty wonky the swarm can get through a Wall of Fire at all.

 

[Bauglir]

However, in the srd at least it is not made clear if the swarm actually _needs_ to attack.

A swarm deals xxx points of damage to any creature whose space it occupies at the end of its move.

This passage is in each swarm. Note that it simply deals damage by having moved into the square, without apparently needing to roll an attack.

And if no attack is made then fire shield would not be triggered..

Yet if that's the case why is an attack bonus listed?

 

[Elder-Basilisk]

Moreover, swarms are immune to effects that target single creatures. Fire shield deals damage to the attacking creature. So there are two rules-lawyerly arguments for swarms to be immune to fire shield even though the description of fire shield and swarms would indicate that it should be very effective against a swarm. (Ad hoc, I'd be tempted to give Fire Shield the area effect 1.5 damage against a swarm at the very least but I'd like it if the rules could be construed so as to make sense without ad hoc fixes).

However, in the srd at least it is not made clear if the swarm actually _needs_ to attack.

 

[Gez]

Swarms don't attack the same way other creatures do. A swarm attack is when it is in another creature's area. So, occupying at the end of the round the same space as someone protected by fire shield is an attack for them, and trigger the normal response.

That's how O would rule it, because that's the most logical thing to do, even if that requires more open-mindedness than the usual D&D rule-lawyerism.

And yep, I like the swarm mechanism. It was needed.

 

[Ycore Rixle]

I was about to type that swarms suffer a -10 penalty to some saves, but checked the SRD first. Good that I did, because they instead suffer "half again as much damage (+50%) from spells or effects that affect an area".

Can you point me to where in the SRD you found this? I can't find it, it must be past my bedtime (Ravenloft game ran late tonight ).

In the Fiend Folio it talks about swarms getting a -10 penalty to reflex saves - and I like that rule very much. We had an encounter with a bloodfiend locust swarm in one game, and it was great.

And overall, yes, I like the swarm mechanic very much.

 

[Celtavian]

re

Even though the rules don't support it, I would allow Fire Shield to be effective against swarms because it logically seems like they would. We DM's have to use our brains sometimes when the rules seem iffy.

 

[Elder-Basilisk]

Yeah. Fiend Folio swarms get -10 to reflex saves from area effect spells that allow saves and double damage from area effect spells that don't.

3.5 Swarms just take an extra 50% damage from area effects whether or not they make the save. (Which unfortunately will work out to them taking less damage overall since -10 usually resulted in more damage (full) than the +50% will (75% on a successful save) considering the bloodwarm locust's +14 reflex save.

The 3.5 SRD info on swarms is strangely broken up. Only half of it is present in the swarms entry. The other half is at the end in the description of the Swarm subtype.

Can you point me to where in the SRD you found this? I can't find it, it must be past my bedtime (Ravenloft game ran late tonight ).

In the Fiend Folio it talks about swarms getting a -10 penalty to reflex saves - and I like that rule very much. We had an encounter with a bloodfiend locust swarm in one game, and it was great.

And overall, yes, I like the swarm mechanic very much.