Gametype Concept ( Friendly Fire mode)

I have no idea if this idea has been brought up before, but I think it would be a lot of fun. To be able to attack you teammates by mistake or on purpose would make for some hilarious plays. Like say zed for instance accidently ulting his own ADC or maybe intentionally who knows. I use that example because I have had quite a few times where I wish I could have for many different reasons. I mean really who hasn't wanted to betray a teammate for doing something ridiculous.

Obviously this would be the pretty far from a serious game mode about winning games. More or less a mode to just forget about your ranked woes and trying to forget the fact that you may be tilting.