Quantified Traits in RPG Play

A great many RPGs define character traits in a fair amount of detail. Just by looking at the character sheet (or with the game stats and a little work), you can determine a character’s capabilities: how much weight can he lift, how fast can he run, how far (and accurately) he can throw, perhaps even other things like IQ, various levels of knowledge, and so forth.

The question is: how much of this raw data provided by character design is actually needed in game play? That is, when do you need to know exactly how far a character can jump? The obvious rejoiner is, “Well, when the character needs to jump over or across something!” But does that challenge require you to know the character’s exact jumping distance, or just how relatively difficult the jump should be? Likewise, is it really a matter of knowing if a superhuman can lift 23 tons versus 26 tons or just knowing she can lift “a bus” but not, say, “a jumbo jet” (at least, not at all easily in the second case)?

After all, the vast majority of challenges in RPG play fall in the relative narrow spectrum beyond the character’s “routine” capabilities (things not even worth making into challenges) but not beyond the character’s “impossible” capabilities. So much so that the capabilities themselves are almost window dressing. Yes, a game system can tell you, for example, that a character can fly at exactly 1,200 MPH, but beyond the fact that the character flies faster than the speed of sound, does it matter much?

It often seems to me like quantified details in an RPG context often just bog things down in needless detail when all you really need to know is a simple plot-point, such as “the character can fly” or “the heroes have access to a jump-capable ship.” The process of defining all that detail is often a kind of game experience unto itself. I recall the lovingly-detailed Champions and GURPS NPCs with full character sheets—Knowledge Skills, Hobby Skills, Quirks, and all—where the vast majority of their game traits never came into play (well, the Quirks, sometimes).

At what point do detailed traits become a detriment to RPG play? Or do they ever?