High Quality Content by WIKIPEDIA articles! In discussion of science fiction, a Big Dumb Object (BDO) is any mysterious object (usually of extraterrestrial or unknown origin and immense power) in a story which generates an intense sense of wonder just by being there; to a certain extent, the term deliberately deflates this. Probably coined by reviewer Roz Kaveney, the term was not in general use until Peter Nicholls included it in The Encyclopedia of Science Fiction as a joke.