So if you have the time and the imagination, why not give them a go. One has a first prize of $20,000 for a 100-word story.
Mash Short Stories
Looking for short stories of no more than 500 words written from a 3-word prompt.
Competition runs every 3 months. Top prize of $100. Current competition closes on 15th October 2014.
http://mashstories.com/competition/
SpineTinglers Short Story Competition
Looking for short stories of under 5,000 words that make the spine tingle. Can contain ghosts, ghouls or poltergeist and even mild erotica. Top prize of 100GBP. Monthly competitions. Current competition closes in 2 days.
http://www.spinetinglers.co.uk
Writers of the Future
Long fiction stories or novellas of 17,000 words or less in the genre of sic-fi, fantasy or dark fantasy. First prize of $1,000. Competition runs every quarter. This quarter closes on 30th September 2014. (and yes, I know this competition is run by the Scientologist, Ron L Hubbard, so please don't email me if you are opposed to scientology. This is just a literary competition :)).
http://www.writersofthefuture.com/contest-rules/
International Flash Fiction Competition
100 word short fiction based on the slogan, "Mandela: Words and Concord." Top prize of a whopping $20,000. Competition closes on November 23rd 2014.
http://www.museodelapalabra.com/en/short-tales-contest/4-edition/participation-form
Comic Book Script Writing Competition
Darby Pop Publishing are looking for a 22-page comic book strip based on the INDESTRUCTIBLE universe. Top prize of $500 plus publication. Competition closes on October 22nd 2014.
http://www.darbypop.com/beyond-the-cover/breaking-into-comics/
Monsters and Marvels Competition
Short stories of up to 12,000 words and poems of up to 300 lines wanted for this short story competition on the the theme of Monsters and Marvels. Top prize of $500. Competition closes at midnight on 1st October 2014.
http://sparkanthology.org/contests/seven/
CareGiver Short Story Competition
A short story competition sponsored by Shield Healthcare. Looking for short stories of 600 words or less about "What Makes Caregiving Rewarding?" Top prize of $500 Amex gift card. Competition closes 30th November 2014.
http://shieldhealthcare.com/caring/caregiverstory/2014/
Mystery Manuscript Competition
Unpublished book-length manuscripts wanted in the genre of malice domestic (mystery without blood, gore and violence; think Agatha Christie). Looking for a synopsis and first 3 chapters of a work in progress. Top prize of $1,500. Competition closes 15th November 2014.
http://malicedomestic.org/grants.html
Essay Writing Competition
Drake University are holding an open essay writing competition and are looking for essays of 3,500 words on any theme and any topic. First prize is $500. Competition closes on 30th September 2014.
US entrants only.
https://drakewriterscritics.submittable.com/submit/14296
Hidden Prize for Prose Competition
Hidden Clearing Books are looking for book-length unpublished manuscripts of 15k-30k words. Winner will receive $250 plus publication plus 25 copies of the printed book. Open to US and CAN residents only. Closes 31st December 2014.
http://hiddenclearingbooks.wordpress.com/2014/09/01/call-for-submissions-hidden-prize-for-prose-2014/