This list is incomplete.
Too often I find myself going YES LET’S WRITE A GAME then hours later, I’m in front of a blank document going, “well, I need a storyline.” Or maybe it’s a monster. Or a weapon.
RPG plot generators
For adding flavour, detail or a side story, random generators can help come up with stuff a bored or uninspired self would not have come up with.
EDIT: I found more! If you’re more familiar with movies/TV/pop culture, then you might get more ideas from tvtropes.org: