To keep it simple because we all seem to have rather busy schedules. These are to be one page comics. That can mean a single panel spread or it can mean a crazy panel-o-rama. Just try to keep it to approximately the size of one 8.5x11 page. This is digital so it'd be the equivalent of that size, I suppose.
We're going to skip over brackets and sign ups and all of that for now. If you want to battle somebody then throw down the gauntlet.
Preferably have artwork at the time of challenge.
You can respond as many times as you like.
People may jump into the middle of other people's battles. If you do so, make sure that you have something worthwhile to interrupt with.
If both combatants decide the feud has come to an end then they may decide if the mob should declare a victor.
Most importantly, have fun!