The general feat Font of Life has as its benefit the following:
Whenever you are struck by an attack that drains energy or bestows negative levels, you gain an immediate saving throw to resist the effect at the standard Difficulty Class of the attack. If this initial save is successful, you avoid any negative levels but you still suffer any other effects of the attack or spell. If this save fails, the attack proceeds as if this roll had never been made (meaning you still receive whatever save to which you’re normally entitled). (Heroes of Horror 122-3)
Emphasis mine, but what does that mean?
Abe is slammed by a wight, which has the supernatural ability energy drain:
Living creatures hit by a wight’s slam attack gain one negative level. The DC is 14 for the Fortitude save to remove a negative level. The save DC is Charisma-based. For each such negative level bestowed, the wight gains 5 temporary hit points. (MM 255)
What does the feat Font of Life enable Abe to do?
Abe is struck by the 4th-level Sor/Wiz spell enervation [necro] (PH 226):
You point your finger and utter the incantation, releasing a black ray of crackling negative energy that suppresses the life force of any living creature it strikes. You must make a ranged touch attack to hit. If the attack succeeds, the subject gains 1d4 negative levels. [...] Assuming the subject survives, it regains lost levels after a number of hours equal to your caster level (maximum 15 hours). Usually, negative levels have a chance of permanently draining the victim’s levels, but the negative levels from enervation don’t last long enough to do so.
If the necromancer rolls a 4, what does the feat Font of Life enable Abe to do?
In Example 1, I assume Abe makes a Fortitude saving throw (DC 14) immediately upon being slammed. Success means he suffers no effects of the energy drain but is still dealt the wight's slam damage. Failure means Abe suffers both the effects of the energy drain and the wight's slam damage. Please, correct me if I'm wrong. However, in Example 2, because of the feat Font of Life, does Abe get a saving throw despite the spell enervation having an entry of Saving Throw: None?
"Who cares? No one ever takes this feat anyway"
My level 8 barbarian (in a party with inconsistent access to the spell death ward) is considering the feat, given the potential commonality of the spell enervation and his inability to defend against it. Although the campaign's wealth by level is average (or even slightly above) the DMG's guidelines, a permanent death ward effect is still a long way off. His massive Fortitude saving throw bonus doesn't help him against negative levels until 24 hours later, which is too long to wait if a vampire's beating the crap out of the party now, and he's a dead barbarian after the second lucky enervation spell from the boss necromancer.