Rat swarm and Expansion

[TallerSpine]

I was looking over utility forms for a druid, so I was looking for size category tiny animals. Rat swarm came up in my search. I did not see anything in RAW that would prevent a druid from turning into a swarm of rats. With Enhance Wild Shape, the druid would pick up the swarm traits (interesting utility form, albeit not overly powerful). But, since the druid is a Jermlaine, I think he would feel pretty comfortable as a swarm of rats.

Here is some text from the SRD on swarms that may be relevant:

A swarm of Tiny creatures consists of 300 nonflying creatures or 1,000 flying creatures. A swarm of Diminutive creatures consists of 1,500 nonflying creatures or 5,000 flying creatures. A swarm of Fine creatures consists of 10,000 creatures, whether they are flying or not. Swarms of nonflying creatures include many more creatures than could normally fit in a 10-foot square based on their normal space, because creatures in a swarm are packed tightly together and generally crawl over each other and their prey when moving or attacking. Larger swarms are represented by multiples of single swarms. A large swarm is completely shapeable, though it usually remains contiguous.

If you think it is stupid to allow a druid to wild shape into a swarm, that is fine, but please understand that for the purposes of this thread, I am already allowing it. I am looking for assistance in determining a best ruling for how psionics will work with this ability. If it offends your sensibilities to think of a druid turning into a swarm, then please consider instead a Hive Mind swarm, but instead of gaining sorcerer spells, it is gaining psychic warrior powers. It knows Expansion and Compression.

Questions:
Suppose the Druid has psionic abilities and manifests expansion. Does he become: One swarm of Small- or Medium-sized rats (one or two sizes larger). Is this even still a swarm?
The rules I just quoted show that Larger swarms are represented by multiples of single swarms, so would that be multiple swarms of Small- or Medium-sized rats? How many swarms would he turn into? There are no swarms with small or medium sized creatures...
Expansion would not increase the size of the individual rats, it would only make him turn into multiple swarms. How many would he turn into?
What about Compression? Swarms are decidedly better when the constituent creatures are diminutive or smaller. So, would Compression turn him into a swarm of Diminutive or Fine rats? When he wild shapes, he turns into about 300 Tiny rats. If he were Diminutive or Fine, would he be 300 or so Diminutive or Fine rats? Or would he turn into 1,500 or 10,000 Diminutive or Fine rats respectively?
Would the space he takes up change?


Edit:
Here is my first thought on what would happen. The swarm rules discuss "larger" swarms as being multiple swarms. So, it seems like the easiest for me to keep close to the rules would be that a swarm that grows larger than Tiny becomes multiple swarms. So, Expansion would increase its space from a 10 foot square to a 20 foot square. That means 4 swarms of Tiny rats. If he uses expansion to increase 2 sizes, that would be 16 swarms of Tiny rats.

For compression, the rules for smaller swarms are that it increases the number of constituent creatures. so, he would become 1,500 Diminutive rats or 10,000 Fine rats.

In each case, he is becoming more rats. This is fine for a Tiny swarm, as both powers increase the numbers of constituent rats. That is consistent, and I like consistency. The problem is with Hive Mind swarms of smaller size. Consider a swarm of Diminutive creatures. When it expands one size, it becomes 4x swarms of Tiny creatures. It is not increasing the number of creatures. It is actually decreasing it slightly. 1,500 non-flying creatures becomes 4x 300 non-flying creatures. Still, it is almost consistent, and I could almost justify it to myself.

What gets inconsistent is what happens when a Fine swarm attempts compression. Now, I have no idea what would happen in the rules, as there are no creatures smaller than fine. Would the power just fizzle? Would it make the swarm invisible to the naked eye?

[Uncle Pine]

You can't wild shape into a rat swarm, and if you could it'd result into you wild shaping into a pack of rats without the (swarm) subtype, which is neither a swarm nor one creature of the Animal type. This is because wild shape is based off alternate form which says "The creature retains the type and subtype of its original form. It gains the size of its new form. If the new form has the aquatic subtype, the creature gains that subtype as well."

The City-Shape ACF (http://archive.wizards.com/default.asp?x=dnd/we/20070228a) allows you to turn into a swarm at 12th level.

Assuming you did retain the swarm subtype when turning into a swarm, for example by being a were-swarm of rats or a were-murder of crows:

- One swarm of Small- or Medium-sized rats is still a swarm for as long as it retain the (swarm) subtype. However, note that according to the swarm subtype (http://www.d20srd.org/srd/typesSubtypes.htm#swarmSubtype) it doesn't take half damage from slashing and piercing weapons, unlike a swarm made up of Tiny rats. It is still immune to crits and can't be flanked:

A swarm has no clear front or back and no discernable anatomy, so it is not subject to critical hits or flanking. A swarm made up of Tiny creatures takes half damage from slashing and piercing weapons. A swarm composed of Fine or Diminutive creatures is immune to all weapon damage.

- A large swarm is completely shapeable, though it usually remains contiguous, and made by multiples of single swarms. A Large swarm is not. "large" and "Large" have two different bearings in d&d. As such, you'd still be a swarm of tightly packed 300 rats.

- Expansion increases your size category to the next larger one (or the one after that, if augmented). If you're transformed into a swarm of rats and retain the swarm subtype, "you" is 300 rats and the next larger size category is Small.

- If you're starting as a swarm of Tiny rats (and you still have the swarm subtype), Compression would make you immune to weapon damage.

- A Compressed swarm of rats consists of 300 smaller, more widely spaced rats.

- "A single swarm occupies a square (if it is made up of nonflying creatures) or a cube (of flying creatures) 10 feet on a side", regardless of its relative size. If you could crank your size up to Colossal while transformed into a swarm of rats while retaining the appropriate subtype you'd be 300 Colossal creatures sharing the same four 5-ft. squares on the grid.

[TallerSpine]

Edit: I accidentally double posted. I tried to delete the post, but it did not delete.

[TallerSpine]

You can't wild shape into a rat swarm, and if you could it'd result into you wild shaping into a pack of rats without the (swarm) subtype, which is neither a swarm nor one creature of the Animal type. This is because wild shape is based off alternate form which says "The creature retains the type and subtype of its original form. It gains the size of its new form. If the new form has the aquatic subtype, the creature gains that subtype as well."

I disagree with your assessment. Not having the type or subtype does not prevent you from becoming the creature. This is why druid can still wild shape into animals even though they do not gain the animal type. I agree that the druid would not have the Swarm subtype, but I disagree that it would not be one creature of the Animal type. It still would be one creature. It would still be a swarm. It just would not have the Swarm subtype. Note that a swarm is the description given at the top of the Monster Entry while a Swarm (capitalized) is a subtype. Since the abilities of subtype are all extraordinary abilities, a druid would pick these up when using Enhance Wild Shape (as noted in my original post).


The City-Shape ACF (http://archive.wizards.com/default.asp?x=dnd/we/20070228a) allows you to turn into a swarm at 12th level.

Again, I disagree. The druid already had the ability to turn into a swarm of type Animal. This allows the druid to turn into a swarm of type Animal OR Vermin. Although, it is not really an improvement over the ability that allows the druid to turn into a Tiny sized animal or vermin, as that would include swarms. This is a poorly worded ability. Perhaps it means that the druid would gain the subtype, but that is definitely not made clear.


Assuming you did retain the swarm subtype when turning into a swarm, for example by being a were-swarm of rats or a were-murder of crows:

- One swarm of Small- or Medium-sized rats is still a swarm for as long as it retain the (swarm) subtype. However, note that according to the swarm subtype (http://www.d20srd.org/srd/typesSubtypes.htm#swarmSubtype) it doesn't take half damage from slashing and piercing weapons, unlike a swarm made up of Tiny rats. It is still immune to crits and can't be flanked:


- A large swarm is completely shapeable, though it usually remains contiguous, and made by multiples of single swarms. A Large swarm is not. "large" and "Large" have two different bearings in d&d. As such, you'd still be a swarm of tightly packed 300 rats.

- Expansion increases your size category to the next larger one (or the one after that, if augmented). If you're transformed into a swarm of rats and retain the swarm subtype, "you" is 300 rats and the next larger size category is Small.

- If you're starting as a swarm of Tiny rats (and you still have the swarm subtype), Compression would make you immune to weapon damage.

- A Compressed swarm of rats consists of 300 smaller, more widely spaced rats.

- "A single swarm occupies a square (if it is made up of nonflying creatures) or a cube (of flying creatures) 10 feet on a side", regardless of its relative size. If you could crank your size up to Colossal while transformed into a swarm of rats while retaining the appropriate subtype you'd be 300 Colossal creatures sharing the same four 5-ft. squares on the grid.

That's an interesting take. I'll consider that. That could make it simpler than what I was originally intending. But, it runs into consistency issues. The description for a swarm does not allow for creatures larger than Tiny to be part of the swarm. It specifies the three size categories of creature that make up swarms, and it seems to imply that creatures larger than that would no longer qualify as a swarm. You are taking the interpretation that even though they are too large to be a swarm, they are still a swarm somehow. I'm not sure how I feel about that.

[Fouredged Sword]

I disagree with your assessment. Not having the type or subtype does not prevent you from becoming the creature. This is why druid can still wild shape into animals even though they do not gain the animal type. I agree that the druid would not have the Swarm subtype, but I disagree that it would not be one creature of the Animal type. It still would be one creature. It would still be a swarm. It just would not have the Swarm subtype. Note that a swarm is the description given at the top of the Monster Entry while a Swarm (capitalized) is a subtype. Since the abilities of subtype are all extraordinary abilities, a druid would pick these up when using Enhance Wild Shape (as noted in my original post).



Again, I disagree. The druid already had the ability to turn into a swarm of type Animal. This allows the druid to turn into a swarm of type Animal OR Vermin. Although, it is not really an improvement over the ability that allows the druid to turn into a Tiny sized animal or vermin, as that would include swarms. This is a poorly worded ability. Perhaps it means that the druid would gain the subtype, but that is definitely not made clear.



That's an interesting take. I'll consider that. That could make it simpler than what I was originally intending. But, it runs into consistency issues. The description for a swarm does not allow for creatures larger than Tiny to be part of the swarm. It specifies the three size categories of creature that make up swarms, and it seems to imply that creatures larger than that would no longer qualify as a swarm. You are taking the interpretation that even though they are too large to be a swarm, they are still a swarm somehow. I'm not sure how I feel about that.

I would point you to the mob template for ideas.

There be no RAW here, but there be guidelines.

[The Viscount]

So I assume for these purposes you are a Druid of level 11 or higher to gain access to tiny forms.

The rules are clear on swarms that they can only be Fine, Diminutive, or Tiny. If you used expansion to become Small, you are no longer a swarm. Use the stats for a normal rat and adjust for the size increase. This business about increasing your area doesn't hold water, as swarms of different sized creatures occupy the same area.

As for compression, I'd say that you remain the same number of creatures, and simply become smaller. The rules for number of creatures in a swarm is for "normal" swarms and doesn't really affect anything except for Hivemind rules, which are broken regardless.

I think they introduced rules for size categories smaller than Fine in one of the Dragon Magazines, but for normal rules Fine does not have a lower bound, as evidenced by things like swarmshifters turning into sand.

[TallerSpine]

So I assume for these purposes you are a Druid of level 11 or higher to gain access to tiny forms.

The rules are clear on swarms that they can only be Fine, Diminutive, or Tiny. If you used expansion to become Small, you are no longer a swarm. Use the stats for a normal rat and adjust for the size increase. This business about increasing your area doesn't hold water, as swarms of different sized creatures occupy the same area.

Yes, the druid is level 15. I don't want to deal with the druid turning into 300 small-sized rats. I don't want to deal with 300 attacks per round. Now, if you are saying that the swarm would turn into one rat with a size category of Small, that is just silly. The druid did not turn into a rat. The druid turned into a Rat Swarm. While composed of rats, it is not a rat itself. It is a swarm. So, I was hoping to maintain the abstraction a little while longer. If I keep the rats the same size category, but just make it so that expansion increases the size of the swarm (turning a single swarm into 4 or 8 swarms), that would be an easy way to adjudicate the size change.

Alternately, I can see saying that the Expansion effect targets just one rat in the swarm, it gets larger and leaves the swarm. I can see the same for Compression. That would negate the effect that these two powers have on Swarm.


As for compression, I'd say that you remain the same number of creatures, and simply become smaller. The rules for number of creatures in a swarm is for "normal" swarms and doesn't really affect anything except for Hivemind rules, which are broken regardless.

I think they introduced rules for size categories smaller than Fine in one of the Dragon Magazines, but for normal rules Fine does not have a lower bound, as evidenced by things like swarmshifters turning into sand.

I am still not sure. I think I might just go with the two powers have no effect on the swarm.

[denthor]

Your the DM your druid becomes a rat swarm.

An opposing mage cast an Iron wall in the form of a circle trapping a portion of the swarm. Say 26 rats from the swarm. What happens to the druid? They can not reunite with the whole of themselves. Where would the body reform inside the iron cage outside? Would it be missing parts arms legs organs ?

Messy thing to do

[TallerSpine]

Your the DM your druid becomes a rat swarm.

An opposing mage cast an Iron wall in the form of a circle trapping a portion of the swarm. Say 26 rats from the swarm. What happens to the druid? They can not reunite with the whole of themselves. Where would the body reform inside the iron cage outside? Would it be missing parts arms legs organs ?

Messy thing to do

I'm probably gonna keep it simple. If it cuts off part of the swarm, it counts as hp damage when he "reintegrates". He is just weaker without a part of himself. But, it can be healed.

[Psyren]

Neither Expansion nor Compression would work:


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.



Range: Personal
Target: You



Range: Personal
Target: You

For both powers, the "specific number" being targeted is one.

[Crake]

Neither Expansion nor Compression would work:







For both powers, the "specific number" being targeted is one.

Was just about to post this, but you beat me to it. +1 to this answer.

[Uncle Pine]

Neither Expansion nor Compression would work:







For both powers, the "specific number" being targeted is one.

Oho, good find. I'll +1 to this as well.

[TallerSpine]

Neither Expansion nor Compression would work:

For both powers, the "specific number" being targeted is one.

Awesome, thanks :).

[InterstellarPro]

Sorry to reopen a question where the OP accepted an answer, but powers and spells only check for valid targets when they are manifest or cast. Once the effect is active, it is active even if its target ceases to be a valid target. For instance, if a character uses Enlarge Person, then Polymorph to become a non-humanoid, the Enlarge Person effect remains active, even though the character's type is no longer a valid target for the spell. The same would hold true for a druid who uses Expansion/Compression and then wild shapes into a rat swarm. So, while it is true that they cannot expand or compress while in swarm form, those forms can certainly wind up being affected by those powers. And then you are right back to where you started trying to adjudicate what the affect may be on such a creature that is never supposed to be the target of a targeted effect.

Edit: The OP's solution in this case seems the most fun (albeit not entirely logical, but still the most fun): The effect does work on the swarm, but it only works on one rat. So, one rat will wind up being larger or smaller than the rest.

What would probably happen is you have a situation where the Wild Shape effect renders the Expansion or Compression irrelevant.


Combining Magical Effects

Spells or magical effects usually work as described, no matter how many other spells or magical effects happen to be operating in the same area or on the same recipient. Except in special cases, a spell does not affect the way another spell operates. Whenever a spell has a specific effect on other spells, the spell description explains that effect. Several other general rules apply when spells or magical effects operate in the same place:

[...]

One Effect Makes Another Irrelevant

Sometimes, one spell can render a later spell irrelevant. Both spells are still active, but one has rendered the other useless in some fashion.

[Psyren]

I'm not clear on what would happen if you manifest Expansion and then Wild Shape. I suspect it would be identical to what happens if you drink a potion of Enlarge Person followed by Wild Shape.

[MaxiDuRaritry]

My suggestion is to just add additional contiguous single!swarms to make up the difference. Simple. Easy.

[InterstellarPro]

My suggestion is to just add additional contiguous single!swarms to make up the difference. Simple. Easy.

I believe this was the OP's original idea, and he decided to just make it so that the powers simply fail to affect the swarm at all.

[MaxiDuRaritry]

I believe this was the OP's original idea, and he decided to just make it so that the powers simply fail to affect the swarm at all.And it was pointed out thereafter that one can still manifest expansion/compression before wild shaping, and it would still work.

[Ashtagon]

A swarm can't be targeted by the expansion power.


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.

[MaxiDuRaritry]

A swarm can't be targeted by the expansion power.But it can still be affected by it if it was something else when targeted -- in this case, a druid.

[InterstellarPro]

A swarm can't be targeted by the expansion power.

This point has already been made. It also does not answer the question of what happens when the druid manifests expansion prior to wild shaping into a swarm. Then the swarm is not targeted by the effect. It is ongoing. I quoted the relevant rules for multiple magical effects. The options expressed so far:

The effect remains active but irrelevant.
The effect functions normally, and you wind up with multiple contiguous single swarms.

The other options have mainly been dismissed.