Something unusual that falls into the category of "writing contests", but definitely not in the mainstream.
The
Bulwer-Lytton Fiction Contest is definitely a bit different: it is a
bad writing contest. Yep. You heard me. The challenge is to produce the worst piece of fiction possible, in the form of an opening paragraph to a story (thankfully you don't have to write the whole story!).
Always worth a laugh to see how badly you can torture prose.
