Snowcasting and Undead.

[Joe Eskimo]

So Snowcasting (the spell that makes all spells cold) requires me to have a Constitution of at least 13 for me to pick it up. As a living, breathing human I acquire it with no problems. But say I somehow become an undead creature. A lich or necropolitan maybe. What happens to the feat? Do I lose access to it? If not, can I still get feats related to it like Frozen Magic or Frostfell Prodigy?

[Pilo]

As soon as you do not have the prerequisites for something, it does not work anymore (you still have it but it has no effect), if it is the first feat of a feat chain, all the feats from the feat chain stop working.
if you use it to qualify for a prestige class, you lose all the class feature, including the +1 caster level in a previous class.

You however keep the hit points, the skills points, the Bab, the save bonus and the global character level.

Rule: http://www.d20srd.org/srd/feats.htm#prerequisites

[Joe Eskimo]

Ok. Thanks!

[Dusk Eclipse]

Actually your hit points would change since you loose your con bonus to hit points, assuming you have con 13 and are level 3 (earliest level to become a necropolitan) you would loose 3 HP, with higher levels and/or higher con mod you would loose even more of the,.

[GolemsVoice]

However, you can ask your DM to let you take the feat anyway. I presume the con requirement hs something to do with being able to withstand the cold or something, and as an undead, you don't care at all about this.

[TuggyNE]

Actually your hit points would change since you loose your con bonus to hit points, assuming you have con 13 and are level 3 (earliest level to become a necropolitan) you would loose 3 HP, with higher levels and/or higher con mod you would loose even more of the,.

I think what was meant is you don't lose hit dice from prestige class levels you no longer qualify for; you certainly do lose bonus HP from Con if you become Undead.