Ability Scores in Roleplaying Games
What's an ability score?
Ability scores are a quantitative means for expressing certain traits of a character within the framework of a roleplaying game.
What do you mean by "certain traits"?
Exact specifics differ from game to game. Most games offer some sort of numerical representation of a character's physical attributes, mental attributes, and sometimes additional attributes as well. This may simply be just two numbers, but most games add more definition than just that.
What's the point of physical ability scores?
Common physical ability scores represent concepts like strength, agility, and endurance. Ability scores allow for two "strong" characters to easily determine which of them is stronger than the other, etc.
What's the point of mental ability scores?
Mental ability scores are somewhat trickier than other kinds. After all, the intelligence of the player may not correspond very well with that of the character. How does a person play a character who is smarter than they are? There no perfect answers. Sometimes particularly smart characters can take up more time to decide on actions, based on the notion that in the game world, they wouldn't need all the time the player is using to work things out. Sometimes game masters are more likely to give hints to smarter characters. My experience tells me that more often than not, intelligence scores mostly just affect mind-based die rolls, like avoiding mind control, or something.
What are these "other" scores?
Most common are "spiritual" ability scores, or "social" ability scores, or some combination of scores related to these categories. These scores are usually directly related to the style of the game in question. For example, the game Mage: the Ascension has an Arete score that describes a character's over-all magical prowess and potential.
To be honest, the things that an ability score can describe are limited only by the industrious imaginations of gamers, ranging from a character's one-ness with universal laws (Mummy: the Resurrection), to the infamous wang stat (prurient house rules of middle school gamers everywhere).
Okay, but why ability scores?
To understand the role of ability scores in roleplaying, one must first know a little about the history of roleplaying games. Although this is a subject that could be spoken about at some length, the important thing to know is that roleplaying games were originally an off-shoot (a "mod", if you will) of war gaming. Pseudo-ability scores existed in war games to show how powerful different units were, relative to one another. This could be a simple one-number system: infantry are 1s, tanks are 4s, and so on; or it could be significantly more involved, with scores for offense, defense, speed, and so on.
These "ability scores" allowed for war gamers to use dice as a neutral judge of sorts, simulating the effects of random chance on a battle. It was this game mechanic that was carried over from war gaming to roleplaying gaming. Ability scores give players a way to determine whether we kill an orc or not, adding a sense of risk, which leads to dramatic tension, which makes a gaming experience more fun and memorable.
However, roleplaying games are ostensibly about more than killing orcs, they are also about telling a story. Players, after all, play roles when they roleplay. From the birth of roleplaying in the 70's through the 80's, most roleplaying culture revolved around the idea that most of the game was about dice and numbers. When a character performed an action, dice were rolled and the results were spelled out numerically. In the 90's, however, we saw the birth of the so-called Storyteller school of roleplaying, which operated under the philosophy that dice should be rolled only when absolutely necessary, and that their results should never derail a good story, even if the game master has to twist, or even ignore the results of dice. In this sort of environment, the role of ability scores changes somewhat. Rather than simply denoting a target number for a die roll, ability scores may determine whether a player must even pick up the dice at all. While a game master might decide that an average character must roll to move a heavy beam off of their leg, a particularly strong character may just be able to do it without a roll at all. This system is taken to an extreme in "dice-less" roleplaying games such as Nobilis, in which ability scores represent a pool of points that characters can spend to perform different kinds of miraculous actions.
So does everybody play by this "storyteller" philosophy these days?
Good heavens, no! The "storyteller" school of roleplaying is usually said to be one end of a spectrum, with the older, more die-focused side usually called the "simulationist" school. Both styles of gameplay remain popular today, and the "which is better" argument continues to set fire to message boards across the internet.
Gotcha. Now go back and explain this "wang stat" thing.
Don't ask me. I didn't play in middle school.