Alright, here's the idea.
You roll 2 dice.
One die applies to the degree of difficulty you're trying to achieve. You try something easy and you roll a d4, something typical = d6, a bit tricky = d8, complicated = d10, truly spectacular = d12. This applies to attempts at awesome combat strikes just as much as it applies to marketplace haggling, feats of agility, or attempts to harness the mystic energies of the world.
The second die applies to your inherent degree of skill when trying to achieve something. If you're not great then you roll a d4, if you're pretty average roll a d6, moderately proficient = d8, naturally adept = d10, instinctive virtuoso = d12. If you have a specific skill associated with the task, you add 1 to the result.
You can generally choose the difficulty die you want, in combat you might have to learn specific tactics that have specific dice associated with them, the same might apply to spell effects.
When you try to accomplish something, you may roll the dice together (specifying which coloured die is the difficulty die and which is the skill die), or may roll the difficulty then the skill (if you've only got dice of the one colour).
As long as your skill die is at least equal to the difficulty die, you succeed in the action. The actual quality of that success is determined by the result of the difficulty die. So you want a high difficulty die for a better chance at a spectacular outcome, and you want a high skill die for a better chance at succeeding.
For example, if you go with a d4 difficulty and d10 skill, the best you'll get is a "difficulty outcome 4" difficulty, and a 70% chance of succeeding with this outcome result. You've got an even better chance of passing at a lower "difficulty outcome". On the other hand if you go with a d8 difficulty, you might end up with a "difficulty outcome 8", and a 30% chance of succeeding, but then again you might still end up with a "difficult outcome 4", and the same 70% success chance. You might even have a d12 difficulty and d10 skill, but if that difficulty die rolls an 11 or 12, there is no chance your d10 will reach that result.
I'm thinking that in this system, rolling doubles might have some added benefit.
It's just an idea at the moment.