Originally Posted by
Sutekh
Depends.
Back in the day, there were three basic types of magic.
Trained magic, which ended up manifesting as telepathy and telekinesis, mostly, and it indeed seems that many magicians like Strange and Mordo and Clea and Jennifer Kale can do, but also various humans taught by aliens, like Moondragon, Mantis and 'Bob' the Uranian / Marvel Boy.
'Personal power,' which seemed to be something Dr. Strange was notable for having 'a lot of' potential for, even before training (which was one of the reasons the Ancient One had such high hopes for him in the first place), which might be the sort of magic that some people can develop, and other people really can't. Personal power was a limited pool, and didn't always replenish itself, so it was possible that some impulsive or poorly trained (or deliberately misinformed...) young wanna-be magicians could show off and 'burn themselves out' before learning to supplement their personal power with the other two less-finite resources.
Invoked power, from generally otherworldly entities like Cytorrak, Watoomb, Ikonn, etc. The sorcerer makes pacts with these entities, and can then draw upon their power, instead of using his own, for certain preset 'spells.' (Crimson Bands of Cytorrak, Winds of Watoomb, Images of Ikonn) Presumably evil magicians could theoretically invoke power from forces like Chthon, Set, Shuma-Gorath, D'Spayre, Mephisto, Loki, the Gibborim, the Great Beasts, etc. but that hasn't been established... In any event, that's just pacts to be made and invocations to utter, which I'd assume anyone could do, regardless of 'personal power.'
None of this may be canon any longer, and it certainly seems that more recent Marvel writers don't know any of it, so who knows.
I would imagine that the 'witches' of the Salem's Seven, for instance, might be examples of folk who have put in the training, perhaps learned a few invocations, but don't necessarily have a ton of personal power, and could never be Dr. Strange level sorcerers. Ditto, Nekra. She's learned some necromancy, but pretty much plateaued there, and would need to invoke power from elsewhere to fuel a big working, or cast something fast and dirty. Quite a few Marvel magic-users seem limited to a lower tier than the magic zaps and shields level of Dr. Strange and company. (For the longest time, Dr. Doom was at that lower tier. He talked big smack about magic, but rarely ever used any. These days, he seems more actively a magic-flinger, as much as a technologist.)