Nintendo loves the number three. I can’t say I blame them; it’s a magic number, after all. When we think about sets, about grouping things together, there’s a sort of bizarre, inexplicable attraction to the number three. Movie franchises with only three films are exceptionally common, to the point that we even have a word for a set of three movies: Trilogy (the term “duology,” which is a set of two connected films or similar works, is hardly ever used,…