Tom S 820 wrote:
Feat Blasting Boulder Source Giant revisited
The boulders you hurl explode upon impact, laying waste
to nearby creatures.
Prerequisites: Smoking Boulder, base attack bonus +13,
heat rock special attack.
Benefit: You can infuse rocks thrown as part of an
attack action with volatile fire energies, adding one of
the following effects to a thrown rock affected by your
Smoking Boulder feat.
Choking Smoke: All creatures in the affected 10-footradius
spread are nauseated for 1 round.
Concussive Blast: Creatures in a 10-foot-radius burst are
deafened and staggered for 1d4 rounds (Fortitude negates).
Incendiary Explosion: The creature struck by this rock takes
4d6 points of fire damage, other creatures within a 10-footradius
burst take 2d6 points of damage, and all affected
creatures catch on fire. A successful Reflex save halves the
fire damage taken and negates catching on fire.
What Stat do you use to set the DC?
Considering the flavor text of the heated rock special ability and the Smoking Boulder feat, I'd say it should be Con.
