Hahahahahahahahhahaha. Nah.
There have been attempts via handbooks to explain the rules of magic in the Marvel Universe, but if you’re not both deeply interested and already pretty knowledgeable, they’re probably going to be boring to you. If you’re still curious, you can look up Marvel Tarot or the Official Handbook of the Marvel Universe sections on magic. A lot of that stuff is on the Internet.
As for Wanda’s magic, it doesn’t operate the same way Doctor Strange’s magic does, but the way that it operates changes with every writer. Englehart’s original conception of Wanda’s magical powers was that they were something she learned entirely from Agatha Harkness. They fit in with her mutant powers in vague ways, but she got them from instruction and training. They were tied to nature because they were based on Neopaganism and didn’t have the kind of (pseudo-)Eastern influences that Doctor Strange did.
The writers who came after did not do the kind of research on Paganism and magic that Englehart had done so they messed up his real world-based approach to her powers. Her powers were still tied to nature under some writers, but how that manifested and what it meant was different from the original intention. Then, in the 80′s, Englehart returned to writing Wanda, and with him, returned those Pagan references, now with a more explicitly Wiccan focus.
But Wanda was still a mutant and some writers very much favored that take on her powers, to the detriment of the magical side. Because Wanda was a mutant first, there was resistance to treating her as a witch (at least without reminding everyone that she’s not as witch-y as those other guys), and so she didn’t get her own fully developed magical system until Busiek introduced the idea of chaos magic. Chaos magic in the Marvel Universe, unlike the Wicca of Englehart, has exactly zero connection to the Chaos Magic(k) of our universe. They share a name, and that’s it.
In addition to her style of magic being vague and ever-changing, Wanda never got the kind of toys that Doctor Strange got. She remained entirely a point-and-shoot character, someone who fires off energy blasts, and didn’t have a levitation cloak or a Wand of Watoomb. (She did have a wand under Englehart, but that was used alongside a chalice, etc. in a ritual in the same way a Pagan in our world would use a wand to direct energy. It had no special properties.)
What you’re talking about when you say Wanda doesn’t draw from an outside source, like some others in the MU do, are models of magic. That’s a real world term that can be applied to fiction. The standard magical models, in our world, are spiritual, energetic, psychological, and information. There’s also a meta-model that’s common among practitioners of Chaos Magick (not to be confused with Wanda’s chaos magic), where the other models are mixed and matched to suit the users needs.
When the Sorcerer Supreme calls upon the Vishanti to expel evil, that is the spiritual model of magic. That is asking a spirit or an otherworldly being to use their power to do something for you. A big part of being Sorcerer Supreme is the connection to the Vishanti, who choose the Sorcerer Supreme, and the power they bestow on that person.
When Wanda waves her hands and chaos magic causes something to explode or the ceiling to collapse, that’s closer to the energetic model. That is her using magical energy that exists around her to do something on her own. Chaos magic may be Chthon’s, but Chthon is not doing Wanda’s bidding when she does a spell. He doesn’t want to do her bidding. He wants her to be powerful and adept at magic, but that’s only for his own ends. She has been imbued with Chthon’s energy and can use it independently of him. She doesn’t need to invoke him in any way.
To the question of whether or not she operates with different rules: Sorta. There’s a lot of point and shooting in Marvel magic, and often the distinctions that are spelled out for us don’t make much of a practical difference. Everybody is firing blasts of energy, and everybody has magic glow hands. I agree that she’s not properly integrated into the mystical side, and that gives her a different, more raw feel than some of the more classically trained magic users in the MU.
