Guidelines...
In the past, I have asked it to be third edition, but I do not think that really matters.
I have asked that the story conform to SR rules, but that has been kind of ignored and/or sidestepped by at least one prize winner.
I asked them to be long enough to make their point and short enough not to lose our attention, but I think I'd like them long enough to tell a story. To be eligible for a prize, I have asked that the story be original and not posted elsewhere on the 'net, and have only noticed one that I had read before. (There are a lot of Dumpshockers surfing the net, hungry to read fiction, and you had better believe they would love to rat you out.

Multiple submissions are ok, but I have heard that if you enter 2 strong pieces and there is another contender, you tend to hurt yourself by splitting your vote.
I have asked that submissions be Titled. And that the PM you send me have the title in the Message Title box. It makes it so much easier to keep track of them, to find them when you send me an edited version, and to represent in the poll so you can get a vote.
Yes, edits will be accepted until contest is concluded. (Meaning even after I have posted them and established the poll. The earlier you get them, the better chance people will understand you.)
I have asked that you Personal Message submissions to me here at Dumpshock. Include the Story title in the submission (or as the message header.) The Personal Message Function can be quickly reached by clicking on the new messages button at the top of the page. One of the features is automatically saving a copy for yourself when you send the PM (I suggest doing this.) I should be able to use the quote function to easily cut and paste without having to go through and format things like paragraph breaks and italics.
It looks like there is interest. GenCon starts August 16th, so I think a deadline for entries will be the 12th. This gives more than a month to create a story, a few days for everyone to savor them, and time for me to deliver the prize in person should the winner be attending the convention. (I may even make a production out of awarding it so you can meet fellow Dumpshockers, and they can see what a freak you really are. Ok you may not think your freaky looking, but I have been a bit surprised to put faces to names, and to find Critias actually does not have horns and cloven hooves. ) In the pleasant event there are many submissions,
I post the submissions without the author's name, hopefully to avoid bias and/or cronyism, and create a poll for the DS community to help choose.
And I am open to suggestions for improvement.