Butch Cassidy is a Western that's injected with more humor and a sense of casual ease between the characters that I've never seen in a Western before, except a flat-out parody like Blazing Saddles. The very nature of the two main characters even lends itself to comedy. Comedy is often based around characters who are insanely stupid or intellectually deficient in some area. Butch and Sundance possess great intelligence when it comes to pretty much everything except they cannot grasp the concept of how much trouble they're going to get themselves into by robbing. Consider the inherent humor of these situations:
- You would think that they went to Bolivia to try to get away from being chased, but once they get down there, they go and start robbing every chance they get. Their excuse is that they don't think they'd make good farmers or ranchers. The scene in which they discuss this with Etta plays out as if they're going to a career cousnelor trying to figure out what their ideal job is and they have no sense of "well, maybe we should pick career choice A or career choice B because career choice C will severely increase our chance of getting killed."
- They think that they're going to be eligible to join the army despite the fact that they're the most wanted outlaws in the West
- They have Etta give them a crash course in Spanish so they can properly rob a bank as if the sight of guns and hand motions won't be enough. Butch also fumbles the presentation of the initial bank robbery and has to resort to some crib notes in his coat picket
- They're chronically inefficient as bank robbers. You would think that like in "The Wild Bunch" or "Unforgiven," Butch and Sundance would try to score one big job that would be enough to be financially secure, but Butch and Sundance rob with no end in sight. They do almost as if it's a weekly 9-5 job they have to show up to work at, as if they have rent and bills that need to be paid. There's no sense of "this is how much we need to buy some land." I don't even get the sense that they're even keeping track of how much money they're making. Etta says that they take too many expensive vacations and are poor gamblers, but somehow I don't buy that explanation entirely.
Lastly, I want to touch up on another source of the film's greatness. The film is great because of the sense of suspense it builds up. Particularly when the railroad-possee is hunting them down and we don't even know who they are, it feels like the shark in Jaws where there's the thrill of an unkown enemy.