One of my players who is running a disease-themed witch is wondering if the empower spell feat would affect the ability score damage done through the Contagion spell (e.g., filth fever, 1d3 to dex and Con). Given that there is a variable effect, I can see the argument in favor of it working. On the other hand, I think the spell is just delivering the disease, not inflicting the damage.
Empower Spell (Metamagic)
You can increase the power of your spells, causing them to deal more damage.
Benefit: All variable, numeric effects of an empowered spell are increased by half, including bonuses to those dice rolls.
Saving throws and opposed rolls are not affected, nor are spells without random variables. An empowered spell uses up a spell slot two levels higher than the spell's actual level.
School necromancy [evil]; Level cleric 3, druid 3, sorcerer/wizard 4
Casting Time 1 standard action
Components V, S
Target living creature touched
Saving Throw Fortitude negates; Spell Resistance yes
The subject contracts one of the following diseases: blinding sickness, bubonic plague, cackle fever, filth fever, leprosy, mindfire, red ache, shakes, or slimy doom. The disease is contracted immediately (the onset period does not apply). Use the disease's listed frequency and save DC to determine further effects. For more information see Diseases.
There are no numeric variables within the spell, so there is nothing for empower to work on. The only thing that happens is you get to choose a disease to immediately affect the creature.
Please note, the effects of the disease are not actually an effect of the spell. The spell causes a disease, the disease is mechanically a separate thing.
By default I'd say that it wouldn't work. That said it seems perfectly reasonable to have it work. Either via a generous GM would think nothing of it, or a GM would fulfill your polite begging request.
If ever something isn't overpowered nor unreasonable, in my opinion the answer should be "sure". If he already thinks you're strong enough, that's something else though I guess.
Some additional context is that this is a disease-themed witch... Disease is not something that tends to have a huge impact on a fight and the player is doing it because he likes the challenge. He is not a min-maxer.
I'm inclined to agree that RAW and RAI would have that the feat does not apply. The spell description's only variable is the type of disease you pick. Past that, it's the disease that does its thing, not the spell. But I can see the opposite argument as not being unreasonable, so I'm inclined to grant an exception in this case.
Anyway, thanks to all for the input. Not sure if the above context on the game helps shape opinions, but additional input is always welcome.