We all know and love (or hate) the expansive list of video game tropes; the TV Tropes wiki has put together a shockingly extensive list (also home of a wiki version ofthe grand list of RPG clichés), spanning all sorts of genres and with plenty of examples. My favourite is "Malevolent Architecture":
Castles aren't large walled structures where people live and work, they're intricate mazes. Temples aren't places where people go to worship their various deities, they're where the ancients practiced their Booby Trap- and Death Course-making skills (and they were so good at it that they are still functional after hundreds of years without maintenance). Even places like warehouses and sewers, where the design should be fairly straightforward, are designed solely to deter intruders, even if there is no earthly reason why it should be so, and even if it utterly inconveniences non-intruders. One wonders what the regular people do.
Oh, so true.