Too late to edit, Wikipedia suggests that Seller would have played four characters, had he not sprained his ankle and passed the role of B-52 captain to Slim Pickens.
I don’t know. Is that the answer that you are looking for? At least 27 different roles, I guess, because Buster Keaton has at least 26 different roles in The Play House. Like Alec Guinness in Kind Hearts and Coronets, it’s a kick to see which role he turns up in next.
We had this question a little while back. as I pointed out then, Peter Sellers has a history of multiple role-playing in films, far beyond Dr. Strangelove: Let’s go Crazy 6 roles
The Case of the Mukkinese Battle-Horn 4 roles
the Mouse that Roared — 3 roles (including Grand Duchess Gloriana)
Soft Beds, Hard Battles – 6 roles (including Adolf Hitler)
The Prisoner of Zenda – 3 roles
The Insidious Plot of Fu Manchu – 2 roles (Fu Manchu AND his nemesis Nayland Smith)
Incidentally, apparently in Dr. Strangelove he was originally supposed to have four rol;es, the fourth being the character eventually played by Slim Pickens
By this logic, I’d rather nominate Deep Roy, who played the Oompa Loompas in the Burton version of Charlie and the Chocolate Factory. As opposed to Agent Smith, the duplicates of Deep Roy were all recorded individually.
I hadn’t really thought about roles that were exact duplicates of each other (like Agent Smith) - even in multiplicity, they’re different characters, but I guess it counts.
In which case, John Malkovich in Being John Malkovich plays a world full of duplicates of himself…
Buster Keaton in The Play House, where he plays everyone on the theater and on stage. I counted at least 25 at the start of it. They are all different characters, too.
Those really shouldn’t count. Hugo Weaving didn’t play multiple characters in the Matrix sequels, they just digitally pasted his face onto a ton of body doubles. I think that’d apply to Malkovich too, although I think there’s a little actual acting in that scene.