Conjuration (Summoning) [see text]
Level: Air 9, Drd 9, Earth 9, Fire 9, Water 9
Components: V, S
Casting Time: 10 minutes
Range: Medium (100 ft. + 10 ft./level)
Effect: Two or more summoned creatures, no two of which can be more than 30 ft. apart
Duration: 10 min./level (D)
Saving Throw: None
Spell Resistance: No
This spell opens a portal to an Elemental Plane and summons elementals from it. A druid can choose the plane (Air, Earth, Fire, or Water); a cleric opens a portal to the plane matching his domain.
When the spell is complete, 2d4 Large elementals appear. Ten minutes later, 1d4 Huge elementals appear. Ten minutes after that, one greater elemental appears. Each elemental has maximum hit points per HD. Once these creatures appear, they serve you for the duration of the spell.
The elementals obey you explicitly and never attack you, even if someone else manages to gain control over them. You do not need to concentrate to maintain control over the elementals. You can dismiss them singly or in groups at any time.
When you use a summoning spell to summon an air, earth, fire, or water creature, it is a spell of that type. (Wizards of the Coast, 3.5 SRD, Spells D-E).
Unlike the spell Creeping Doom (see Summoning Magic, Part 2: the Creeping Doom for more on this spell) there is no need for us to invent a third party intermediary for use in making Elemental Swarm functional in relation to how summoning magic works. Yet there is a rather large variable in how many elementals heed your summoning.
Now why is that?
According to our understanding of summoning magic (see Summoning Magic for more on this topic) our magic user has a connection to the summoned creatures that allows them only to pull a single creature – that we are magically bound to - of any given type into this world. Yet here we are presented with a variable amount of elementals that come to us when we summon them. Why?
While it is entirely possible that our magic user is able to make multiple connections to different elementals, binding each to them as they do so, we are still left with the question of variablity. Namely, if we have bound these elementals to our service in such a way that they can be summoned into this reality, then why are some of them able to defy our call?
Two answers come to mind.
On the one hand we could determine that the reason for variability comes from the elemental’s innate nature which allows them to defy our summons at times, while at others they must heed us. Yet, on the other hand, we could say that our binding is to a single, powerful elemental, who heeds our call by sending his subordinates in his stead. This would explain the variability and hold to our original understanding of summoning magic with out introducing a needless check for determining the elemental's resistance to our summoning.
As this spell is a ninth level spell and would only be used by the most powerful of magic users it seems reasonable to assume that our magic user would be bonded to a powerful entity - one that might be able to pull on the magic user as well.
My natural inclination is to have the magic user bonding themselves to the Elder Elementals. Perhaps without fully realizing the danger inherent in using these powerful beings early on, but with a growing understanding of the deadly potential this relationship represents for them. Maybe something similar to the way that characters in H.P. Lovecraft's stories slowly become aware of the corrupting nature of the forces their wielding . . .
I'll need to give this idea more time to marinate. More later.