Question regarding swarms

[Greenfield]

The spell Flaywind Burst from Sandstorm generates a 70 mph wind with scouring grit. 60 foot cone, D6 of damage per caster level.

It also details how far various sized creatures are blown back, and what (if any) damage they take from the movement. (Fliers really take it in the chin on this one.)

Now consider the effect on a Swarm. Should we count the size of the swarm, as a whole, or the size of the critters that make up the swarm?

Also, what happens to a swarm if part of it is in the areas, and thus subject to being blown away? Does the entire swarm get moved? If not, how do you adjudicate "half a swarm"?

The situation is about to come up in our game, and I'm running the character about to cast the spell. While I definitely have a preferred direction for some of these answers, my wishes actually have no impact on the outcome, since I'm not the DM.

 

[frankthedm]

What swarm will survive the damage of the flaywind spell? Area Attacks deal 50% more damage to swarms IIRC.

Now consider the effect on a Swarm. Should we count the size of the swarm, as a whole, or the size of the critters that make up the swarm?

I'd use the size of the individuals.

Also, what happens to a swarm if part of it is in the areas, and thus subject to being blown away?

I'd say dispersal. EDIT: Retracting this statement, was not thinking about the higher CR swarms.

 

[Greenfield]

What swarm will survive? In this case I'm not sure what the exact monster is. The Dm was using MM3, and I've carefully avoided looking it up because that would be cheating. (My character doesn't have the Knowledge - Nature chops to identify it, and he doesn't happen to own a copy of that book. )

I do know that each swarm is a CR 12, that there are 6 of them, and that we have 5 PC's of 10th or 11th level.

Did I mention that I'm probably going to have to make a new character soon?

As for my question, I should have checked the SRD:

A swarm is immune to any spell or effect that targets a specific number of creatures (including single-target spells such as disintegrate), with the exception of mind-affecting effects (charms, compulsions, phantasms, patterns, and morale effects) if the swarm has an Intelligence score and a hive mind. A swarm takes half again as much damage (+50%) from spells or effects that affect an area, such as splash weapons and many evocation spells.
Swarms made up of Diminutive or Fine creatures are susceptible to high winds such as that created by a gust of wind spell.
For purposes of determining the effects of wind on a swarm, treat the swarm as a creature of the same size as its constituent creatures. A swarm rendered unconscious by means of nonlethal damage becomes disorganized and dispersed, and does not reform until its hit points exceed its nonlethal damage.

So a swarm of Fine insects is about to take it in the teeth. Cool!

Sadly, the SRD doesn't describe what happens when a Swarm is dispersed by effects like this.

 

[Vegepygmy]

For purposes of determining the effects of wind on a swarm, treat the swarm as a creature of the same size as its constituent creatures. A swarm rendered unconscious by means of nonlethal damage becomes disorganized and dispersed, and does not reform until its hit points exceed its nonlethal damage.

Sadly, the SRD doesn't describe what happens when a Swarm is dispersed by effects like this.

"...dispersed, and does not reform..." seems fairly clear to me.

 

[Noir le Lotus]

For effects based on size, you must use the size of the individuals of the swarm. In fact, the size of the swarm is already the size of the individuals.

A centipede swarm may occupy a space of 10x10 ft, but it is defined as a Diminutive Vermin (Swarm).

PS : a little tip to help you get out of this situation Gust of Wind

"A Tiny or smaller creature on the ground is knocked down and rolled 1d4×10 feet, taking 1d4 points of nonlethal damage per 10 feet. If flying, a Tiny or smaller creature is blown back 2d6×10 feet and takes 2d6 points of nonlethal damage due to battering and buffeting."

The damage is small but the push effect helps greatly against swarms !!

 

[Greenfield]

"...dispersed, and does not reform..." seems fairly clear to me.

Check the beginning of that sentence: If knocked unconscious by non-lethal damage...

And yes, Gust of Wind is nice for this sort of thing. Flaywind Burst, which I mentioned, is Gust of Wind on steroids. Stronger winds, plus actual damage.

The remaining question, which applies to both Gust of Wind and Flaywind Burst is, what happens when only part of the swarm is in the path of the spell? Does the entire swarm get pushed back? (That seems wrong.)

Is the swarm automatically scattered? (That seems wrong too.)

Does the swarm cling together, ignoring the "push back" effect? (Again, it seems wrong.)

Splitting the swarm seems the most reasonable, in a real-world sense, but it makes such spells into automatic swarm-killers.

I'm trying to come up with a fair and reasonable answer, lest my DM's answer be neither fair nor reasonable.

 

[Vegepygmy]

Check the beginning of that sentence: If knocked unconscious by non-lethal damage...

Right. What's your point?

If the effect doesn't deal nonlethal damage (or doesn't knock the swarm unconscious), the swarm isn't dispersed. But if it is dispersed, it is effectively destroyed until it can reform.

Am I missing your point?

The remaining question, which applies to both Gust of Wind and Flaywind Burst is, what happens when only part of the swarm is in the path of the spell? Does the entire swarm get pushed back? (That seems wrong.)

A swarm is treated as a single creature, so I would say yes.

Is the swarm automatically scattered? (That seems wrong too.)

Automatically? No. But swarms are extremely vulnerable to such effects because the entire swarm is treated as if it is only the size of its individual units.

 

[Greenfield]

Right. What's your point?

If the effect doesn't deal nonlethal damage (or doesn't knock the swarm unconscious), the swarm isn't dispersed. But if it is dispersed, it is effectively destroyed until it can reform.

Am I missing your point?

Yes, you are.

I'm not asking about the effect of damage, I'm asking about the effects of blow-back by a wind effect, if the effect covers only part of a large swarm. Does it move the whole swarm, even the part that's not being blown? That makes no sense at all.

Does it leave the swarm unmoved, despite the fact that the component creatures are sitting in a 75 mph windstorm? That makes no sense either.

Option 3 would be that it moves part of the swarm, effectively dispersing it. That makes wind-sheer effects into insta-kill for swarms, and while that makes a certain amount of sense, it nerfs swarms down to nothing. In our case, several CR 12 foes potentially taken out by a single 3rd level spell., one that does almost no damage.

We have three potential answers, all supported by the rules to one extent or another, without an actual good answer among them.

 

[Binho]

Yes, you are.

I'm not asking about the effect of damage, I'm asking about the effects of blow-back by a wind effect, if the effect covers only part of a large swarm. Does it move the whole swarm, even the part that's not being blown? That makes no sense at all.

Does it leave the swarm unmoved, despite the fact that the component creatures are sitting in a 75 mph windstorm? That makes no sense either.

Option 3 would be that it moves part of the swarm, effectively dispersing it. That makes wind-sheer effects into insta-kill for swarms, and while that makes a certain amount of sense, it nerfs swarms down to nothing. In our case, several CR 12 foes potentially taken out by a single 3rd level spell., one that does almost no damage.

We have three potential answers, all supported by the rules to one extent or another, without an actual good answer among them.

I would interpret that the swarm would be dispersed, until next round, when they would be gathered together. That would maintain the swarm immobile for 1 round. Is that acceptable by the rules?

 

[frankthedm]

I'm not asking about the effect of damage, I'm asking about the effects of blow-back by a wind effect, if the effect covers only part of a large swarm.

If half the swarm is blown away, just split the swarm into two parts until the part that is blown away has the time to fly back. Hitting only half the swarm shouldn't be more beneficial than hitting the whole thing