It's not exactly football. It's actually a little closer to rugby, but it does involve fighting! As Salt put it "it's like mobile MMA," because it is legal for you to beat the hell out of any member of the opposing team (not just the guy with the ball), and if you get knocked out or injured your team cannot bring in a sub. It's like the polar opposite of soccer!
Still having trouble figuring this out? No problem, we have a whole game to show you. Check out the Rome...I'm gonna guess "Gladiators" against the Florence...let's call them "Gladiators."