In any sufficiently long-running movie franchise, recasting is inevitable - everybody hates it, but on a long enough timeline, it's basically unavoidable.
There comes a time when actors either lose interest in a part, are unavailable due to scheduling conflicts, or sadly pass away, and so producers are left with no choice but to hire a new actor to play the role.
And in some rarer cases it's actually an active, motivated decision on the filmmakers' part, to change the direction or look of a character, or hire a more high-profile performer if the character gets a bigger role in sequels.
It's relatively common to see characters recast once, which is difficult enough, but sometimes characters end up suffering a bout of chronic recasting, where across a single iteration of a franchise they're played by three, four, or even more actors.
How successful this is really depends on the nature of the franchise - comedy generally gets away with it far easier than drama, but if they're a high-profile character, there's sure to be growing pains regardless with each recast.
Indeed, Hollywood just couldn't settle on a single actor - or even just two - to play these roles...
10. Kitty Pryde - X-Men
X-Men's Kitty Pryde is an interesting example to kick things off, because despite there being no discernible time jumps between the first three X-Men movies, the decision was nevertheless made to recast the character in each successive film.
In the first X-Men, Kitty appeared in cameo form as played by Sumela Kay, where we saw her phase through a wall before Professor X (Patrick Stewart) verbally confirmed her to indeed be Kitty Pryde.
In X2, Kay was replaced with Katie Stuart, who appeared briefly during William Stryker's (Brian Cox) assault on the X-Mansion.
But for threequel X-Men: The Last Stand, Kitty Pryde was given a far more substantial role, and so director Brett Ratner quite unsurprisingly decided to cast a more established name actor in the part.
And so, Elliot Page became the third and final performer to portray Kitty Pryde in the X-Men movie franchise, ultimately playing the role in both The Last Stand and X-Men: Days of Future Past to solid acclaim.
Though a Kitty Pryde solo film was also in the works at one point, this was eventually nixed following Disney's acquisition of Fox.
And with the X-Men surely making their debut in the Marvel Cinematic Universe sooner rather than later, there's a fair chance we'll see another new take on Kitty in the coming years - albeit within an entirely different continuity, of course.