Put Franchise/TheDarkTower-related trivia here.

* RealLifeWritesThePlot: Stephen King was run over and almost killed by a van between writing the fourth and fifth books. This winds up being ''very'' important in the story, foreshadowed through the fifth and sixth books and seen in the seventh, where [[spoiler:Roland's ''ka-tet'' are directly responsible for his survival.]]
* The word "slughorn" used in the original poem "Childe Roland to the Dark Tower Came" is actually a medieval word for "slogan," meaning "battlecry." Browning used it to mean an actual horn after reading the 18th century poetry of Thomas Chatterton, who seemed to believe that the word indicates a musical instrument. This is a little ironic given the end of the Dark Tower series, in which Roland cries out his arrival, but discovers that he needed to have a horn.