The idea - participants of the contest will make a fanfiction piece to the Labhrainn series - i.e Heart of Winter and/or Hounds and Bitches. The stories are originally written by ~anubishoarmurath and myself. (And they can be found in my gallery, in case you have no clue what I'm talking about.)

Wiki says about fanfiction:
Fan fiction is a broadly defined term for fiction about characters or settings written by admirers of the original work, rather than by the original creators. Most fan fiction writers assume that their readers have knowledge of the canon universe (created by the writer) in which their works are based.

So, now you know
Mediums? Any you can imagine - digital painting, photomanipulation, traditional drawing, short story (novel ), poem, photo, fluffy stuffed Keith - the limit is only your imagination and the term - fanfiction. So - it has to be connected to the world of Labhrainn and/or the characters.

Feel like tossing Gordon and Belaric through a wormhole unto Mars - go for it. The limit is your imagination, like already said.