Champthrax said:
Cheating in real life is bad for the same reason it's bad in a game: any victory you achieve through cheating is completely hollow because you didn't earn it yourself. While in a game, using cheats simply removes any challenge from the game, and without challenge a game loses its purpose. But cheating in life actually has consequences. You cheat to get into law school, you use knowledge that is not your own to pass the entrance exam. Alright, now you're in law school...what now?
Well, you either have to make up for all the knowledge you DIDN'T have to begin with by studying your ass off, or you just keep on cheating your way through. Assuming you don't get caught and kicked the fuck out, you'll end up graduating with a law degree and go on to become a lawyer...what now?
Well you'll either go on to be one of the shittiest lawyers ever since in truth you have no idea what the hell you're doing because your degree was gained via knowledge that you didn't truly know, or you'll just stick with what got you through law school: your "cunning", and try to cheat the system to win your cases. You'll then most likely get caught, disbarred, and end up flipping burgers anyways. Why? Because you didn't get to where you were on your own, you used the talents of other people to get you there. When there's no one left to cheat off of, you're left with nothing but a stupid look on your face because, again, you have no idea what you were doing...where as had you taken the time and effort to actually study for the entrance exam and study your way through law school, you WOULD know what you were doing, and could therefor go on to make a career as a lawyer for yourself.
This applies for pretty much everything. Would you have much confidence in an engineer that cheated his way through school? Or an architect? Or an accountant? Another thing to keep in mind is that cheating inherently implies dishonesty, and most people don't like working with dishonest people.
But beyond all that, you said it yourself in your OP: life isn't fair. If you're not smart enough to get into law school on your own, guess what? You probably shouldn't aspire to be a lawyer. Life isn't fair and it's not meant to be fair. Using cheating as an attempt to balance things out to make it "fair" for you makes it "unfair" for others that DID put the time and effort into studying and such. So why is the "fairness" of your life more important than the "fairness" of the lives of the people you cheat off of? What makes you so important? FUCK YOU YOU DAMN CHEATING BASTARD!

Just kidding with that last bit, just kidding, but yeah, there's plenty of reasons why cheating is bad. :3
What's fair in life is doing the best you can with what you've got, not doing the best you can with what the person beside you has.