This one was quick. I never liked the idea of Necromancers being some really weird class, ONLY concerned with Undead and death. My take on them is essentially that they took a liking to animating dead when they were apprentices and possibly spent a lot of their spare time with the local priest. Since they essentially are just "better" Magic-Users, they have a higher XP cost to advance. This is another class that requires good roleplaying to pull-off: necromancers don't bother with crap like magic missile. I'd go so far as to paint them somewhat pacifistic in the sense that they deal with death so much they'd rather not cause it if possible. Paradoxically, these are the guys who WOULD be hanging out with a bunch of fighters descending into the depths of a long-lost labyrinth, due to their fascination with decay and entropy.
No idea what the deal is with the table below. It's coded correctly, yet still prints about 20 /n characters. Stupid blogging software...and then I tried to fix it with a monospace font, but it converted all the tab stops to spaces. CSS was supposed to make formatting so much easier, wasn't it? Oh, and I'm finally DONE with all the alternate spell-casting classes. Yeesh, that took a while. On to the fighters and thieves.
Requirements: INT 12, CON 12
Prime Requisite: INT
Hit Dice: 1d4
Maximum Level: None
Necromancers are Magic-Users who prefer to deal with the Undead. They can control Undead much like clerics, but for all other purposes act as Magic-Users. Whatever applies to Magic-Users applies to necromancers as regards armor, weapons and fighting ability. While not necessarily evil, they are private individuals who prefer acting subtly. Most Necromancers do not bother learning flashy spells such as fireball or lightning bolt, and most see evocation spells as akin to using a hammer to drive in screws.
Spell Casting: Necromancers cast spells in exactly the same way as Magic-Users (see MAGIC-USER SPELL PROGRESSION chart pg. 16 LL:AEC). They can use Magic-User scrolls and magic items.
Control Undead: Necromancers can Control Undead in much the same way as chaotic Clerics (see TURNING UNDEAD TABLE pg. 13 LL:AEC). They perform this ability as a Cleric of two levels higher (e.g. a 5th level Necromancer affects Undead as a 7th level Cleric). A Necromancer rolls 3d6 to determine the number of HD of Undead affected. At 5th level this increases to 4d6, and 5d6 at 9th level. Undead will serve until destroyed or controlled by a rival cleric/necromancer.
Reaching 9th Level: As per Magic-Users.
Reaching 15th Level: The Necromancer can begin researching lichdom if he so chooses. Not all Necromancers select this path; those that do make it their primary goal. The resources and time required are left to the DM's judgment, but 1-2 million gp and several years (if not more) are recommended.