As both a referee and a player, I have a thing for the undead. They're among my favorite monsters in D&D and I like to use them as often as I can without lessening their impact. I'm sure there are some deep-seated psychological defects on my part that explain my fascination with walking corpses.
I also love the idea of specialized magic-users. Unfortunately, I've never seen them done in a way that really appealed to me. They've all been deficient in some way or other, but the most consistent flaw in my opinion is the sacrificing of flavor for mechanical compatibility and vice versa. What I want is a specialist MU that feels noticeably different than a "standard" one but whose supporting game mechanics aren't too bizarre.
Combine these two facts with the growing prominence of the city-state of Yethlyreom in my Dwimmermount campaign and it was inevitable that I'd try my hand at coming up with a necromancer variant for use with OD&D/Labyrinth Lord. What follows is a something I've been intending to introduce into the campaign to represent NPC necromancers. I'd also allow it for PCs, too, with the caveat that necromancy is not a common magical specialty and, in the current campaign area, is known only in Yethlyreom, whose magic-users are none too keen to share their secrets with just anyone.
The text in the quote box below is hereby designated Open Game Content via the Open Game License.
Necromancers are magic-users who have plumbed the secrets of life and death in order to gain power over both. Necromancers use the same experience point charts as ordinary magic-users and must abide by the same weapon and armor restrictions. However, at various points in their progression (as noted in the chart below), necromancers gain the option to exchange a single spell slot for the use of a new ability unique to their class. These abilities are spontaneous, meaning that they do not need to be prepared ahead of time like spells (though they can be, if so desired) and can be used at any time so long as the necromancer has a single unspent spell slot of the appropriate level. Necromancers also have access to a number of unique spells, described in Part III.
Character Level (Spell Level)
Pass through Undead
Energy Drain Immunity
Pass through Undead: Gained at 2nd level, this ability expends a 1st-level spell slot per use, granting the necromancer the ability to move among undead beings without being attacked for 6 turns. This ability affects only the necromancer not his companions. Likewise, intelligent undead get a saving throw versus spells to overcome this ability.
Sleep/Charm Immunity: Gained at 4th level, this ability expends a 2nd-level spell slot per use, granting the necromancer immunity to sleep and charm person spells, as well as abilities and magic items that mimic those spells, for 6 turns. If the necromancer is willing to forever sacrifice a 2nd-level spell slot, this ability becomes permanent.
Command Undead: Gained at 6th level, this ability expends a 3rd-level spell slot per use, granting the necromancer the ability to command 2D6 undead to do his bidding. The necromancer is treated as if he were a cleric three levels below his actual level, with a successful turning roll or "T" result indicating that the undead unquestioningly obeys the necromancer for 1D4 hours and a "D" result indicating obeisance for 1D4 days. This ability can be reapplied later, but each reapplication requires a new roll (if applicable) and the expenditure of an additional 3rd-level spell slot per re-application (i.e. the first re-application expends two 3rd-level spell slots, the second three, and so on).
Paralysis/Hold Immunity: Gained at 8th level, this ability expends a 4th-level spell slot per use, granting the necromancer immunity to all forms of paralysis and hold person, as well as abilities and magic items that mimic them for 6 turns. If the necromancer is willing to forever sacrifice a 4th-level spell slot, this ability becomes permanent.
Animate Dead: Gained at 10th level, this ability expends a 5th-level spell slot per use, granting the necromancer the ability to create any combination of corporeal undead whose total hit dice do not exceed his level. These undead obey the necromancer and remain animated until they are destroyed or until dispel magic is cast upon them.
Energy Drain Immunity: Gained at 13th level, this ability expends a 6th-level spell slot per use, granting the necromancer immunity to all forms of level drain, whether cause by undead or some other source. If the necromancer is willing to forever sacrifice a 6th-level spell slot, this ability becomes permanent.