In Final Fantasy XI, all Goblin enemies have an ability called Bomb Toss. It hurts your entire party a fair amount when it hits, but sometimes the Goblin drops the bomb and blows itself up. This is a flat percentage chance to happen, but for years there were rumors that you could “force” the Goblin to drop the bomb by moving in certain ways, or hitting certain abilities, or any other sort of weird set of actions.
None of these did anything, of course. And I tried all of them. In fact, for a long time I swore that “take a quick step left, then two steps right” would cause an assured bomb drop. It was, of course, not true and did not work that way, which makes it one of the longest false rumors I believed for a distressingly long time. And having shared my story now, I’m eager to hear yours. What false MMO rumor did you totally buy into at one point, even though you now realize it wasn’t correct?