Mark Millar seems to think there's a chance. But the numbers from Kick-Ass 2 make it seem unlikely. Which is an opinion shared by the stars of the films.
Speaking with Comic Book Resources about finishing the comic book series Kick-Ass 3, the question was naturally asked if there was a film adaptation on the way. Millar answered:
I can tell you exactly where we're at. I'm always 100% straight up with these things — to the point where I'm always revealing stuff two or three years before it's supposed to get out. I know I told you immediately after we got the first weekend after "Kick-Ass" came out that we were doing "Kick-Ass 2." And Matthew [Vaughn] had engaged Jeff [Wadlow] by the following September, but no official announcement was made until the following year. But what you can always do is look at the opening box office to see how much money it's going to take in and see what the development possibilities will be.
With "Kick-Ass," it was a no brainer. It was made for $28 million and made $100 million back and then made another $140 million on DVD. So for the money guys, it was a $28 million investment that made $240 million. That's a slam dunk. You're getting your sequel. The second one didn't make as much. It cost a little less at around $24 million, made $61 million and made about $100 million again on DVD and TV rights. It was still profitable. It was by no means "The Lone Ranger." But does that mean we'll make another one again? I don't know. It's definitely up in the air, and we'll just have to see. Matthew is a guy who I trust to make that decision. If he decides he does want to do it, I know he'll get it done well. And he's got the movie rights, so it's ultimately his decision. I speak to Matthew every day, and we haven't discussed "Kick-Ass 3" so who knows? The option is always open.
If Millar is trusting Matthew Vaughn to make that decision and Vaughn hasn't mentioned in their talks every day, it seems unlikely that the sequel is coming. But more than that is the issue of the money. Kick-Ass 2 had a production budget of $28 million, which just about equal to how much the film made domestically. Even ignoring marketing costs, which can and often do equal production costs, that means that all of the film's profit came from overseas and home release, which is not ideal. And this wasn't a case of a film doing okay business in the U.S. and doing very well overseas, which has rescued many a film's sequel prospects.
On the contrary, Kick-Ass 2 made around $32 million in foreign markets. Only four million more than at home. Contrast that to Pacific Rim, whose foreign box office more than tripled its $101.8 million domestic gross.
If you want good news about a Kick-Ass 3 film, the fact that the films have kept their budgets small and even managed to decrease its budget between the first film and sequel is a factor in its favor. So is the fact that none of the cast has ruled it out. Although Aaron Taylor-Johnson's comment last year that he didn't have a contract for a third movie isn't great, at least from a budget perspective. Like Chloe Grace Moretz, he has a lot of films on his plate and fitting this one in seems like a difficult cast.
In May, Christopher Mintz-Plasse also expressed the opinion that the second film hadn't made enough to justify a third film:
I haven't heard anything. You know, the second one didn't make that much money, so it's hard to make a third one when there's not a big audience for it. I mean, I would love to put an end to the series, but as of right now, I don't think anything's going to happen.
You know, I hope, I wish [for a third film] That's be fun. That'd be great. I doubt it, but I would love it.
... The hard thing is if fans want a third movie, they've got to go buy the ticket to go see the movie. It was like the second most pirated movie of the year, so if you want a movie to be made into a second, a third, a fourth and a fifth, go buy a ticket. Don't pirate it.
Moretz and Mintz-Plasse seems much less optimistic about Kick-Ass 3's chances than Millar is and are more concerned about the numbers. Combined with Millar saying the film's chances are in limbo and that we live in an age where sequels are announced early, they're probably right to be pessimistic.