I was perusing an old issue of Dragon this afternoon- one printed well before I was born- and I came across an interesting little system for attribute checks. It is a little clunky and probably has more math than the whippersnappers* of today's gaming can probably handle, but the thing I like about it is the variability; a character who has a Strength of 12 doesn't always have a base chance of 60% to accomplish something with a Strength check. You have your good days and your bad. It's not a perfect system, but I think it might be usable.
Ok, check this: you roll percentile dice, adding the character's actual score. The result will give you a die type, ranging from d4 to d12. You roll that die, multiply it by the character's attribute, and that is their chance of success for the task at hand.
So, if our Clever Rogue with an Intelligence of 16 is trying to figure out how to read the magical scroll he has found before the angry sorcerer who owns it can blast him with magic, roll percentile dice, adding 16. Our result is less than stellar and determines that a d4 will be used. We roll a 3 on the d4. Multiplying that 3 by our "hero"'s 16 Intelligence, we get a 48%... his chance of reading the scroll correctly before he gets a face full of Prismatic Excellence.
I should add, at this point, that the author suggests optional modifiers: adding the character's experience level to the initial roll, for instance. He also advocates letting any character try anything, offering several suggestions for modifying the roll based on suitability of character class to task. He has an example for letting a Fighter try to pick a lock and use a magic item normally useable only by magic-users. (Though admittedly their chances are pretty low, as well they should be- of you're going to have a game with character classes, they ought to be the best at what they are intended to be best at...)
Now, I like the idea of the system, but I have the notion that it ought to be streamlined a bit. After all, we are making three die rolls and several small calculations to resolve one task. That won't do at all. So, howzabout this simpified version:
We skip the initial die roll to determine which die to use. Instead, the DM dtermines the die based on how difficult the task is. So, something very hard will use only a d4, while a simple task might use a d10. You roll, multiply it by the ability score, and there's your chance. You could even say that different characters use different dice in the same situation; our Clever Rogue might only get a d6 to read the scroll mentioned above, but his poor friend the Dull Witted Swordsman might only get a d4. Meanwhile, their Marvelous Magician companion might get a d10 or even d12 to read the magical scroll, as he does specialize in this sort of thing.
I know some will not like this system because it requires two rolls and a calculation, but I find the variability factor to be very interesting. I find that some games, particularly those in which there is a Perception skill or score, are filled with samey dice rolls where everybody rolls Perception to search everything all the time, or in which every single party member makes the same Strength roll to open the same sarcophagus or door or lift the leaden tankard of ale or whatever.