Q: Dear Sage,
Does a warforged benefit from the vigor spells in Spell Compendium?
A: Yes, but the warforged would only get half the normal value of fast healing, rounded down.
Thus, the lesser vigor spell would be useless to a warforged (fast healing 1 halved, rounded down, is fast healing 0).
Vigor or vigorous circle would provide a warforged with fast healing 1, while greater vigor would grant fast healing 2 to the warforged.
About the Author
The Sage is a mammal classified in the bear family, Ursidae, native to central and southern China. Debate continues as to whether he is truly a bear or more related to the raccoon rather than the bear, or perhaps in a family of his own. When not eating bamboo and answering rules questions, he works under the nom de plume of Andy Collins as an RPG developer in Wizards of the Coast R&D, where his development credits include Complete Mage, Dragon Magic, and the Player's Handbook v.3.5. He can be easily recognized by his large, distinctive black patches around the eyes, ears and on his rotund body.