How in the ... oh, right. I knew The Elder Scrolls IV: Oblivion was a glitchy game, but hot damn, this is insane.
Almost every speedrun out there involves some sort of exploit in order to shave off precious seconds of game time (or in this case, hours), and the Oblivion speedrun located above is no exception.
By falling through the map, the speedrunner is able to initiate the game's final quest, completely skipping all of those pesky fetch missions.
While the video has no sound due to its creator being cheap and using demo software, it's still one to sit through.