Readiness and willingness to believe on the basis of little evidence.
Thrillers and action movies only succeed if they don't strain our credulity too much.
Credulity most often appears in the phrase "to strain credulity," but a particularly far-fetched story may also be said to stretch credulity or to put demands on or make claims on our credulity. Credulity is not always a bad thing. There is no limit to the credulity of Boston and Chicago baseball fans, for example, and that probably makes life bearable for them. The related adjective is credulous. F. Scott Fitzgerald once defined advertising as "making dubious promises to a credulous public" -- that is, a naive or gullible public.