Dr. Checkmate, guest blogging over at Uncle Bears, writes:
I know what he means about granularity, but my experience is that more than about five doesn’t actually make much of a psychological impact. Too fine a gradation, even if statistically significant, tends to get lost in people’s mental model of how things work. Despite D&D 3+ grading attributes on a 3-18 scale, what actually matters is the -2 to +4 that usable characters tend to end up with. Similarly, even though each Skill rank in D&D “matters”, the difference between 7 or 8 ranks in a Skill tends not to get noticed. Even in systems like Hero and GURPS, which have you rolling 3d6 against a stat, the bell-shaped curve means that some points are more equal than others. In my own home-brew before I switched to Savage Worlds I used a 1 to 10 scale for both Attributes and Skills, but realistically PCs had about 3-8 in anything the actually did (except for some combat monsters that I actually kind of wish weren’t so crocked). Having a smaller spread in the general stuff but extra Disadvantages/Advantages actually seems to help players think of the characters as having distinct strengths and weaknesses, as well as opening up more actually playable characters. E.g. middling Dexterity stat but Fumble-Fingers Disad giving a minus to fine manipulation is more memorable and easier to work with than an rock-bottom Dexterity score, which in many systems is a death-sentence.
I sometimes wonder if something like the seven-plus-or-minus-two rule is at work here. If a player can’t distinctly visualize all the steps at once, do they just chunk it until they can?