When Dan Stevens decided he wanted to leave Downton Abbey, the writers and producers were faced with a problem. They couldn’t force Stevens to keep working – and yet it would be difficult to give Matthew an exit that made sense inside the show’s universe. Simply upping and leaving his responsibilities would be out of character. So they resolved to kill him off, invoking the ire of many of the show’s viewers, who found the death cheap and melodramatic (especially so soon after Jessica Brown Findlay had left in similar circumstances). This is a problem which affects a great deal of film and TV today: the connection between characters and the actors that play them.

The challenge facing most programme-makers is to achieve the ‘great lie’: ensuring characters and stories exist consistently within the rules of the world they have created. With regard to actors, this means that they must be ‘believable’– so you could imagine their character looking, sounding and acting like their facilitator. While occasionally there is a piece of woeful miscasting, people generally fit their roles at least passably (there is a whole industry based around casting). The larger issue is those actors who do it well. For some, this means typecasting – whether through their skill or natural similarities, in the audience’s eyes they are their character. Ironically, they have succeeded in creating a character so realistic that now their appearance anywhere else illuminates its artificiality.

So what do you do when actors leave?

Characters’ storylines often have to veer wildly from what may have been expected in order to fit with their actors’ lives. They age quicker, have other commitments and sometimes (in the most unfortunate of cases) pass away. Probably the most organic way to deal with an actor moving on is to simply replace the cast members with new characters that fill similar roles. This can vary in effect. In some cases it inspires greater creativity, as in Being Human. Necessity acted as the father of invention due to former cast members changing commitments, but new actors ended up revitalising later episodes after a sluggish season three. On the other hand, another genre show, Misfits, suffered from a question of relevance as the original cast almost all died, emigrated or were incarcerated. The introduction of new characters felt forced, and too much time was spent integrating them into the world whilst not entirely convincing us of their significance. By the end of series four, things looked more promising – but it had taken the length of those episodes to get there. More characters means more exposition, and that means less actual story.

Perhaps a simpler solution is just recasting a character. In The Fresh Prince of Bel-Air, Vivian Banks was recast a couple of seasons in, and despite the huge differences between the actresses there did not seem to be much of an effect on the show. More recently, Game of Thrones has occasionally recast minor characters whose importance has grown in later books. This can be jarring in a more basic way than characters behaving or leaving oddly, but if handled well it can maintain the quality of story to a greater degree. If the audience is willing to play along, there is no reason for the characters to leave with the actors.

Doctor Who and James Bond have built recasting into the very structure of their franchises. A weakness becomes a strength through the recognition that restructuring long-running characters is often a plus. In Doctor Who, the jarring effect of recasting even becomes canonical. Thanks to the ‘renewal’ idea brought in to replace original Doctor William Hartnell, by the Tom Baker era the show had the concept of ‘regeneration’ firmly in place. Admittedly this is easier in a science-fiction show where the rules are different, but the James Bond franchise’s approach (before it was the all-conquering juggernaut that it is today), kept the series fresh with every new 007. 

Could Downton’s Matthew have been saved? Probably not. The sight of Dan Stevens bursting with light and morphing into another actor would probably be too much even for the most die-hard of fans, and the structure of the show means that it couldn’t feasibly have been reconstructed without him. But it’s important to remember that actors don’t own characters, and that creative consistency is the most important thing.