While most of the individual X-Force members, like Wolverine, could fit into the PG-13 boundaries of the main X-Men movies, the team’s adventures as a whole couldn’t be done justice unless the movie earned an R rating.
While the X-Men and X-Force are both comprised of characters who want to keep the innocent protected, the latter team is more willing to get their hands dirty out in the field.
So when X-Force eventually hits theaters, we can look forward to the members going on a gritty mission that will see them making tough choices in order to make sure they complete their objective.
Introduced to the comics in the early 1990s, the X-Force has gone through many incarnations over the years, but most of the time, it’s a militaristic group of mutants who have no qualms about killing to ensure that the world stays safe.