This is an idea I've talked about before. It uses the same mechanics found in many board games. The idea is that you draw one "Event Card" at the start of each round, and that card has some effect, positive or negative, that effects all the teams.
Example:Together with Warmasters (and Card Curator if he doesn't join the War), we would produce maybe 20 of these Event Cards, and then just randomly pick one for each round. It would bring something new to each round, opening new possibilities for strategy, and making the event more interesting.
Opinions?
P.s. Please don't post Event Card ideas here. When Event Cards come as a surprise it's more fun as opposed to everyone knowing the cards and simply waiting for the right one to appear. If you have some good ideas, just PM them to me and I'll see that you'll get the credit. Also we reserve the rights to make any changes to your original idea.