The PopSci Predictions Exchange (PPX) is one of PopSci.com's signature features. With three new "props" to consider each week, users place bets on the outcome of real world science news, maintaining individual portfolios and competing for fame within the game as high-ranking players, and for awesome monthly prizes. Now, in the name of innovation, we've gone and made a good thing better. We are pleased to introduce (drum roll please): PPX Leagues! Seasoned trader or total newbie, you can create and join as many leagues as you like. Grab your friends, family, colleagues and classmates and get started. You make the rules, you determine the prizes. Ah, freedom. Ain't it sweet?