Marvel movie fans are all about continuity, which is really to lifeblood of sustaining something as massive and sprawling as the Marvel Cinematic Universe. Every new addition to that universe needs to be consistent with what's preceded it, and that will include the explanation and use of magic in Doctor Strange.
We already know from interviews with the cast and crew that Strange will involve a metaphysical explanation of magic that fans are already relating to everything from Ant-Man's introduction of the quantum realm, to Doctor Strange possible introduction of the reality Infinity Stone (crucial to Thanos' plans for Avengers: Infinity War).
It may be a geekier detail to get hung up on, but Doctor Strange will also need to balance its use of magic against a character we've already seen using the mystic arts: The Avengers' Scarlet Witch. Wanda Maximoff (Elizabeth Olsen) got her powers through Baron Strucker's experiments - and really they've never been concretely defined - but to fans who saw Olsen onscreen doing funny hand motions with bright light effects, the comparisons to Doctor Strange will be inevitable.
Comicbook.com was on the set of Doctor Strange, and we spoke to Marvel Studios head Kevin Feige about how Strange and Scarlet Witch relate in terms of their use of magic. But according to Feige, there isn't much comparison at all, since Doctor Strange was being conceptualized as Scarlet Witch's powers in Age of Ultron were being completed in post-production. That's the behind-the-scenes explanation, but as always, Feige has a way to rationalize things within MCU continuity:
"Her powers, she's never had any training, I'm talking about Scarlet Witch. She never had any training; she's figuring it out. Arguably, you could say that that's why her powers are much more chaotic and much more loose in the way that we showcased those light effects. In [Doctor Strange], some of what you might see today, even the cover of Entertainment Weekly, it's much tighter. It's all about focus. It's all about pulling energies from other dimensions in an organized and purposeful fashion, which is why they can do a lot more than she can in, at least, a much more precise way."
While Feige's explanation is suitable (for now), Marvel Comics fans know that Scarlet Witch and Doctor Strange have a history of crossing paths, with mystical ramifications that affect the entire Marvel Universe. For really savvy Marvel fans, Scarlet Witch non-mastery of her powers are the sort of dangling thread that can go from being a convenient continuity fix, to the centerpiece of a major MCU crossover event that could, say, explain how the X-Men find their way into the MCU.
Doctor Strange opens November 4, 2016; Guardians of the Galaxy Vol. 2 – May 5, 2017; Spider-Man: Homecoming– July 7, 2017; Thor: Ragnarok – November 3, 2017; Black Panther – February 16, 2018; Avengers: Infinity War – May 4, 2018; Ant-Man and the Wasp – July 6, 2018; and Captain Marvel on March 8, 2019