Why Deadpool Won't Join The Marvel Movie Universe
One of the coolest parts about Deadpool is that it features easter eggs referencing multiple Marvel properties, not just X-Men. The movie's finale takes place on an old SHIELD styled helicarrier, and Deadpool even name drops Samuel L. Jackson's Nick Fury at one point. It would be amazing if Deadpool actually joined the rest of the Marvel Cinematic Universe, but it's likely never going to happen. Here's why.
The basics
Just to set things up, Fox currently owns the film rights to the Deadpool character, and the 2016 movie exists completely separate from Marvel's Cinematic Universe. Deadpool was created by Marvel Comics, but the company sold off the rights to the character back when nobody was making comic book movies. A few years ago, Marvel was bought by Disney, along with all of their film properties. Currently, movies based on Marvel characters are some of the highest grossing movies in the world. Unfortunately for Disney, Fox still owns the film rights to many Marvel characters, including Deadpool. And it's going to stay that way for a long time because...
Fox keeps the rights as long as they keep making movies
With the box office success of 2016's Deadpool, it's incredibly unlikely that Disney will ever be able to buy the film rights from Fox. With a record breaking opening weekend in the middle of February, the price for the rights just skyrocketed. Right now, Disney's only hope of getting the rights is to wait for Fox's option to expire. Fox doesn't own the rights forever, they have to have a film in production within a certain time period or else the rights revert back to Marvel. The exact time period for Deadpool has never been publicly confirmed by either party, but based on other franchises, it's generally believed that this period is 7 years. Deadpool was so successful that a sequel is pretty much guaranteed, most likely to be released in late 2017 or early 2018, which resets the 7 year countdown. Not to mention the fact that it seems likely Deadpool will appear in movies like X-Force, further pushing back the countdown. Basically, we'll all be old and gray before the rights to Deadpool could even possibly revert back to Marvel. It gets even more complicated than that though...
Literally, any X-Men movie
Once again, it's unclear how things were specifically broken down in the agreement between Fox and Marvel, but it's generally believed that Fox bought the film rights to the X-Men franchise, including all related characters. Deadpool likely falls under this umbrella, which means all Fox has to do to retain the rights to Deadpool is put any X-Men movie into production. If the timeline starts to get close, Fox could put a Jubilee movie into production and claim the rights for another period. It's possible that Disney could try to argue against this, but that would probably just end up with the film rights getting stuck in legal red tape, and costing Disney a ton of money. Even if there is some sort of loophole for Disney to make a play for the rights, there's no way Fox doesn't fight for it. It's actually better for Marvel to just let Fox keep making movies, especially because...
The merchandise rights
When it comes to making money, selling t-shirts and stickers can be way more profitable than making movies. Films are expensive, and a lot of people need to get a cut. Regarding Deadpool merchandise, things once again get complicated. Starting in late 2014 or so, fans started noticing that Marvel merchandise was strikingly devoid of X-Men and Fantastic Four characters. It was never officially confirmed, but many believed that this was because of movie rights. The thing is, Marvel only has to share the profits on merchandise based on the movies. With the huge success of Deadpool, it seems like Disney has come around and started allowing X-Men merchandise to be released again, albeit as long as it's based on the comics. So, as far as Marvel is concerned, successful movies mean people buy more merchandise. As long as that merchandise features images from the comics, that profit is all Marvel's. So really, Disney doesn't need to fight to get the film rights back, because we're all buying Deadpool t-shirts anyway.
Spider-Man was in worse shape
If Marvel was able to work a deal with Sony for Spider-Man, then they should be able to work out a similar deal with Fox, right? Well, that was a different situation. First of all, Sony sold the merchandising rights to Disney, which is why there's a ton of Spider-Man merchandise. Second, Sony's Amazing Spider-Man reboot was failing to launch, especially after Amazing Spider-Man 2. Sony had a problem, but so did Disney. It made sense for both companies to work together. Also, Spider-Man is the entire franchise. By having that one character appear in Marvel movies, it reinvigorates all of the side projects Sony was hoping to launch. Meanwhile, Fox's X-Men series is in really great shape, and Deadpool made it even stronger. Even if, down the road, the Deadpool sequels bomb, Fox can just find another part of the X-Universe to mine for ideas. Fox doesn't need Marvel to save their franchise, and Marvel isn't making merchandise for X-Men movies, so neither company really cares if the other succeeds.
They'd lose everything that worked
If Marvel eventually did find a way to steal Deadpool from Fox, they'd risk losing Ryan Reynolds. When Spider-Man came to Marvel, the franchise had to be rebooted and recast to fit with Marvel's vision. Ryan Reynolds spent years working to get an R-rated Deadpool made, so he might not be cool with making a PG-13 version for Disney. Reynolds was such a big part of the film's success, so audiences might not be too excited to see someone else play the character. It's too big of a risk for Marvel.