This carries over to fiction: Think of your favorite show and describe to yourself what makes it good. You will probably think about a combination of likable characters, well-thought out plot, fancy special effects or animation, and a plethora of other positive qualities. None of those things are random. Even comedy that tries to sell itself as 'random' has gags and jokes written deliberately to seem like they're random, while something that is truly random does not make any sense.
If you're watching a movie and, just when things are getting good, the main character gets run over by a car and the movie abruptly ends... You will probably be a little bit upset. We could make the argument that the movie is realistic, but that does not make it good. Odds are that if you were to deliberately write a piece of fiction that does not seem to make sense and has an ending that no one could have seen coming then it is bound to draw negative attention.
This summarizes the last two episodes of Evangelion perfectly.
How come then that Roleplaying Games always have such an intrinsic element of randomness to them? And specifically why would a game centered around the notion of simulating Mecha Anime & Manga leave whether a character lives or dies at the whims of the dice gods?
Randomness can lead to a lot of moments that are simply unfun. Randomness means that you will sometimes fail to do anything meaningful because you keep rolling ones, and you cannot do anything to change your luck! When the same bad thing happens to you time and time again in a game, for no real fault of your own, that's annoying.
OH COME ON THIS IS LIKE THE THIRD ONE!
An Unexpected Development
It turns out that we humans do like randomness, just in small and measured doses. The doses are so small and measured that we often simply call it "surprise" instead of randomness. Randomness as surprises, as opposed to randomness as nonsense, are a desirable thing in entertainment, especially in Games.
A plot or character that never pulls any surprising twists is often a boring one. In the same way, you don't want to know exactly what will happen when you sit down to Roleplay. If you already know how things will turn out, then why are you doing them? Everyone has expectations, sure, but when all expectations enter the game you have to find out how they all fit together. A good resolution will carry an element of surprise for everyone in some way. This is part of the reason we use dice: Randomness does not play favorites.
It might seem contradictory after all that has been said about it, but randomness gives everyone equal opportunities. When two PCs are sparring against each other, their owners can come up with all sorts of justifications to argue that their PC should be the victor. Annette's Player argues she should win because she is the better fighter and she has the moral high ground. Barry's player argues he should win because he is better equipped and the savvy underdog always beats the cocky veteran. Dice do not care about any of that, and under their tyrannical rule there is no room for dissent. All you can do is plan around the idea that luck can be with or against you.
Planning. That's the key to it all. Randomness creates unexpected adversities, rewarding you for creating a character who can overcome the challenges that the story presents to the group. When it comes down to it, Roleplaying is all about solving problems. Some you solve by looking for the right skill or weapon in your character sheet, some with the assistance of other PCs or NPCs, and some you solve by thinking outside the box. Randomness means that sometimes your Plan A fails and you need to resort to a Plan B, combining all the above examples.
Because you never know for sure if you'll succeed or fail, it keeps things from being repetitive. It guarantees that the fifth time you do something will continue to be exciting, which is kind of an important quality if you want to be playing the game for a long time. You never know what challenge you'll be facing next, and while that does not qualify under randomness (unless your GM has tables of randomly generated scenarios and adversaries) it certainly qualifies as surprise.
Imagine spending your starting cash preemptively buying these.
Different Strokes (of Luck) for Different Games
So if we can agree that having an element of chance is desirable, the next question is just how much should be left up to chance. It is a considerably more complicated question, because different games have different needs and thus leave completely different amounts of their gameplay up to chance. Why use dice instead of, say, cards? Why ten sided dice instead of six or twenty sided? Just how much of your character's destiny should be in the hands of lady luck? What if the entire process of character creation was left to the whims of the dice? Those are subjects I'll elaborate on next week.