As the Cyrodiil's Mages' Guild has banned the use of necromancy throughout its membership, no self-respecting mage, including your character, practices the dark art. Throughout your journey in "The Elder Scrolls IV: Oblivion," you'll frequently encounter necromancers who raise the dead using evil, cursed magic, giving you a glimpse of the power you can't wield. Although there is no way to join the necromancy faction as a player without the use of mods, you can build a character that uses a very similar magic style. In fact, reaching 70 skill in Conjuration causes people to comment that you "smell of death."
Important Attributes to Consider
Although any character regardless of race can learn the art of Conjuration, some races are more proficient in it than others.
Breton: The best race for Conjuration magic are the Bretons, thanks to the 10-point Conjuration skill bonus they start out with.
High Elf: If elves are more your cup of tea, go with the Altmer race, known in-game as a High Elf, for half the bonus. When selecting the rest of your attributes, aim for Willpower over Magicka; while you may want more of the latter to increase your mana pool, it's more important that your minions and skills are powerful.
Alternative: If you've already created your character, you can either start over or use console cheats to improve your attributes.
Creating Spells That Mimic Necromancy
Once you leave the sewers for the first time, you can head straight for any major town, speaking with the head of the Mages Guild to join. After joining, you can create your own spells: This is the heart of your journey to matching the other necromancers.
Beginner Spells: For starters, you can create spells with effects like Summon Skeleton or Summon Zombie, both of which summon undead creatures; the only difference between these spells and true necromancy is that you don't have to sacrifice someone to get your minion.
Advanced Spells: Additional creatures you can summon include a Headless Zombie or a Skeleton Champion, which are stronger than their counterparts. The strongest creatures you can summon at Master Conjuration include Dremora Lords and Frost Atronachs.
Improving Textbook Learning
Casting created Conjuration spells functions as practice: Your Conjuration skill increases each time you cast a spell. Your Conjuration skill displays as a number from 1 to 100; the closer you are to 100, the better you are at the skill.
Beginner Trainer: To help you advance your skill quicker, there are a few trainers you can speak with at certain levels of expertise; when you're just starting out, give fellow guild member Sulinus Vassinus in Skingrad a heads-up, and he'll teach you what he knows.
Expert Trainer: Speak with Alberic Litte in Chorrol when you reach Expert Conjuration at skill level 75.
Practicing Without Committing Murder
Warning: Even casting a spell with a harmless element, such as Fear, on people in town is considered a hostile action: The guards will set a bounty on you for assault at the minimum -- at the maximum level, expect only death. If a spell you cast causes someone to die, expect the full 1,000-gold murder charge to appear.
What to do: To level up your spells safely, stick to the uninhabited forests between towns, or seek out hostile enemies and wildlife to let your creations have a taste of combat.
The only way to become a true, bonafide necromancer in "Oblivion" is to install a mod. Several mods add a necromancy faction to the game that the player can join; each mod will have different consequences or benefits. For example, Mysterious Bear's mod lets you build a lair while Dan's Necromancy mod allows quest-related NPCs to die. Some mods, like The Dark Arts Initiative, enable you to truly embrace your evil side by capturing townsfolk and turning them into prisoners.