Big Dumb Object

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 by its mere existence; to a certain extent, the term deliberately deflates this.

The term was not in general use until Peter Nicholls included it in The Encyclopedia of Science Fiction as a joke in 2000, while its creation has been attributed to reviewer Roz Kaveney.

Big Dumb Objects often exhibit extreme or unusual properties, or a total absence of expected properties:

Such unexpected properties are usually used to rule out conventional origins for the BDO and increase the sense of mystery, and even fear, for the characters interacting with it.

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