Good luck keeping track of Tatiana Maslany's clones on Orphan Black.
Generally speaking, playing one character in a long-running hit TV show is plenty of work for an actor, but sometimes circumstances call for them to play more than one person in a series - perhaps several more, in fact.
For one of many reasons, an actor might be asked or required to play more than one character in a TV show, whether for heightened in-universe reasons or simply because the showrunners loved the actor enough and wanted to use them more.
And so, these 10 actors all ended up playing many characters - by our definition a minimum of three, but generally far more than that - throughout these beloved TV shows.
In some series the visual similarity between characters was absolutely acknowledged and totally part of the creative conceit - in the case of relatives, clones, and multiversal variants - while in others it amounted to little more than giving the actor more to do for the sheer fun of it.
Though this sort of tricky casting has massive potential to backfire or seem a little too cute for its own good, thankfully in these examples fans largely loved it...
10. Brent Spiner - Star Trek
Brent Spiner is of course best remembered for his unforgettable portrayal of Data in Star Trek: The Next Generation, but that's far from the only character he's played across various Trek media.
Spiner also portrayed two other androids modelled after Data's creator Doctor Noonian Soong - Lore and B-4 (the latter appearing in the film Star Trek: Nemesis and making a cameo in disassembled form in Star Trek: Picard).
He's also been given the opportunity to play four separate members of the Soong family: elderly cyberneticist Noonian Soong himself on The Next Generation, his ancestor Arik Soong in Star Trek: Enterprise, and in Star Trek: Picard he portrayed both Noonian Soong's son Altan Inigo Soong and another of his ancestors, Adam Soong.
In The Next Generation's season four episode "Brothers," Spiner even played Data, Lore, and Noonian Soong at the same time in the very same scene, per some digital trickery of course. Incredible.
Spiner is set to reprise the role of Lore in Picard's upcoming third and final season, though it wouldn't surprise anyone if he also pops up as yet one more member of the Soong empire.