How do I make a random player picker script?

I'm making a build battle game and I want to know a script on how to pick a random player to be judge, if judge then the player gets like gears and rates players' work with either "SUPER POOP", "POOP", "OK", "GOOD", "EPIC", "LEGENDARY" Its like Minecraft I know

You can use math.random and some variables to have a script pick a random player. http://wiki.roblox.com/index.php?title=Random_numbers