Rule #1: While I'm not a stickler for grammar (especially in dialogue), I am a stickler for spelling -- especially in the "your"/"you're" department. If you're the type to write something like "your funny," please be aware that it will be corrected before going online.
Rule #2: No fan fiction. This project is designed to test the strength of our own world creations. Fan fiction, while it can be incredibly creative, works within the bounds of a world that has already been created. Therefore, if you sneak Remington Steele into a story, or suddenly beam the characters aboard the Enterprise, your segment will not be used.
Rule #3: No graphic depictions of sexual content. While romance is sometimes a necessary plot device, graphic sex scenes generally add little to a story. Characters can have sex... just don't "show" us. If you include graphic sex in your submission, it will be heavily edited.
Rule #4: Most importantly, stay within the continuity of the story. If Egghead Muckleberry is a known liar, thief, and killer, having him suddenly the model citizen would be outside the established continuity. (Change of heart is one thing, but it's a gradual process, if you catch my drift.) Similarly, if we have "seen" Egghead steal something and you try to convince us that someone else did, that is also an unacceptable contradiction. You will be asked to re-write the sections in question to fit continuity. (This does not mean that just because Julia SAYS she's pregnant she really is -- and if you prove her to be a liar, that is perfectly acceptable... as long as it hasn't actually been *shown* she's pregnant.)
That's it! Let your creativity run wild! (If other issues arise, they will be discussed before a "rule" is made out of them.)
Have fun!