They read about it in books. Try it sometime.

From the beating of dead horses.

>>48263361
It depends. A necromancer is a specialization, not a methodology.

Wizards generally get their power by understanding how the world works and manipulating the laws of reality.

Studying.

Stay in school and then go to university, kids.

>>48263361

depends on the setting.

In mine it's everyone who can use magic, can instill some sort of life in the dead. Another reason why they are persecuted and why almost everyone can cast Raise Dead.

In my setting, Necromancers are only a thing because ages ago some kid went and killed the Reaper.

Now there are Necromancers that roam around and collect the built up souls and use them to re-animate dead bodies.

>>48263361
OP normally i hate this response but this is a really low effort question

depends on the settingw

You can enact magical forces on a corpse to make a sort of weird, flesh golem type thing, but there aren't really necromancers in my setting.

Unless you count "vampires", who have some skill with certain types of life magic and can create more of themselves, thereby bringing undead into the world by reproducing, if you count them as undead.

>>48263361
>I know that sorcerers get their power from themselves, and that most other get their magic from a patron that can be a god, demon or nature itself.
It sounds like you're talking about D&D, so I will mention that what you are describing is the Necromancy Wizard school. Being a wizard, their power is not innate, but taught or studied. It is "Arcane" in nature. They are learning to manipulate the forces that make up their universe, and in this case, it usually is the force of "negative energy" to cause death or unlife.

The will is the motive force that allows sentient life to exist and is essentially the energy of the soul.

people who use magic learn to manipulate nature with their will typically over things that do not possess a will of it's own (i.e. the elements).

A corpse can be raised by a necromancer who instills it with his own will but it's not considered undead more so then a flesh golem. Depending on the individual Necromancer's strenght of will he can control one corpse or 20 at a time.

The forbidden arts of Necromancer is actually building a phylactery and containing the soul in a vessel , usually a corpse. If it's the actual body of the soul used to inhabit it works better but generally you can force a soul to inhabit a body that wasn't theres although it creates more complications.

>>48263361
they eat lots of salt. salt is magically aligned with death, and gives people death powers. also cardiovascular problems so necromancers don't usually live long.