 Fun, we should talk about this. What is fun? Fun, if we want to really mechanically explore it, is what some random player of a game wants from that game. I hope no one's playing games for some reason other than fun, unless you're being paid to play games. So, this is what you should be seeking. But this is where it gets interesting. Utility is a game theory term. All right, so you're playing a game and it's like the game, the design of the game wants the players to want something. That something is utility, right? I just said baseball, right? In baseball, if the game wants you to get runs, runs are the utility, right? Settlers, the game wants you to get victory points and then win, right? So victory points are the utility, right? Counter-strike, the utility is kill the other team, plant the bomb, rescue the hostages, those are the utility, right? Anything else you might do in the game is not the desired utility that is from the game design.