I know it’s hard to imagine a time when there was no such thing as a proper “spoiler.” There was no internet to speak of, so leaked information from a film set didn’t get disseminated with the same viral ferocity that it does now; no one was uploading entire scripts for the whole world to see, and, best of all, no one was self-righteously but "accidentally" spoiling anything by railing against things that they perceive to contain spoilers (this is the worst offense of all, to me -- if I don’t know that something is a spoiler, please don’t let me know that one exists; let me live in ignorance until its reveal). If Robin Hood: Prince of Thieves was released in 2011 instead of 1991, Sean Connery’s cameo would’ve been discussed to death via Twitter for months in advance, to the point that we all would’ve been highly disappointed when he only shows up to smile and watch Kevin Costner kiss Mary Elizabeth Mastrantonio in the final minute of the film.
In 1991, however, it was actually kind of awesome. No one was going around saying, “You’ll never guess who shows up at the end of Robin Hood!” or “I don’t want to spoil anything, but stay for the kiss!” It was a genuine surprise. Robin Hood and Maid Marian are getting married in Sherwood Forest, and someone rides up on horseback and interrupts their wedding. That someone turns out to be King Richard, played by an uncredited Sean Connery, who effortlessly wins over the audience simply by showing up, like only a movie star in the middle of a hot career renaissance can. It’s a nice little cherry on a stale cake of a movie; the very definition of “send ‘em home happy.”
The best cameos are unexpected without being distracting, and both Connery’s surprise appearance and the timing of his walk-on are pitch perfect in Robin Hood: Prince of Thieves. This is how you do the stunt casting cameo right -- the right person in the right part, revealed at just the right moment.