Half fiend Dread Necromancer

[The Shadow Lich]

Will a half fiend human dread Necromancer turn into a lich at 20th level? I think no because it is a outsider. But as you know Orcus who was a outsider was undead for a time. How did he do it?

 

[DarkJester]

Dread Necromancer says "A dread necromancer who is not humanoid does not gain this class feature". Half fiend says "The creature’s type changes to outsider." So it does not look like the half fiend human dread necromancer will gain the benefit.

Now, rules aside, I see no reason to prohibit this and in my games I would allow it for either npc or pc.

 

[DiceGolem]

At least according to Vile Darkness, Orcus is still an outsider. It's all in the backstory, I'm afraid.

Not to say a fiendish lich wouldn't be altogether impossible with a quick DM fiat. Vile Death (spell from SC) allows undead to gain the fiendish template, so I think it would be completely in your power to let your Half-Fiend grab the Lich benefits. It'd be up to you to choose between the resulting type, undead or outsider, but if our pal Orcus is an example...

 

[Thurbane]

Maybe instead of half-fiend, give the character Demon or Devil bloodlines, and they might still qualify.

 

[Gestalt]

Libris Mortis has a Lichfiend variant Lich for evil outsiders. I think the only difference is a change in damage reduction types, probably so it involves silver or cold iron.