New mode: FF (Friendly Fire)

What do you think about a game mode where your offensive abilities can damage teammates? Team fights in this mode might be pretty chaotic or at least changed drastically, but the same could be said for URF, and I think people became accustomed to it. I thought of it as primarily something fun/novel, but maybe It also might encourage you to think about every single person's position and get you into the habit of communicating more (especially when you're about to ult into the fray to prevent collateral damage).