I agree that its not 100% clear, but I'd lean towards the spell's effect being a substitute for the normal breath weapon effects instead of being an add-on.
Thanks for the response.
I agree that its not 100% clear, but I'd lean towards the spell's effect being a substitute for the normal breath weapon effects instead of being an add-on.
FWIW, note that Spell Compendium changed the spell, weakening it quite a bit: the SC version is 5th level, and it's an area dispel (that is, you can only dispel one spell per target). SC also specifies that "Spells are dispelled prior to the effect of your breath weapon being resolved", which implies the breath weapon does have its regular effect.
I suspect the Draconomicon version was intended to be blast + dispel, too, but the targeted dispel made it too strong for 4th level, so they weakened it in SC.
For giggles, the dragon could dive into a low strafe carrying a load of Itemized boulders, casting the Antimagic Field at the last possible moment...
The Field will negate the Item spell while the boulders are within its radius...resulting in a sideways avalanche right below the dragon as it passes over the party. (Depending upon a variety of options, the dragon may even be breathing on the party at this point.)
As the dragon completes its strafe, the Field will cease to affect the boulders, and they will revert to their miniaturized state.
Am I evil? I'm a lawyer!
5) Some cool tactic involving a magic item (Instant Fortress) or spell (Rope Trick)
Given time and a bit of OCD, a spellcasting dragon who likes the boulder bomb tactic could use Shrink Item over and over and over again, building up an arsenal of tiny, clothlike boulders...
Then, flying over the party with his arsenal, he says the trigger word while releasing them...resulting in either a cluster bomb effect (if released simultaneously) or a carpet bomb effect (if released sequentially).