I always thought the D20 systems suffered from their eponymous die of choice: 1 to 20 is quite a large range of result in relation to the flat bonus a character can generate in the beginning and the the fact that each result has the same probability hamper the capacity of players to estimate how their character would fare in face of a given threat.
And so I thought, why not makes the roll with 2D10 instead when the PC are in some way competent with what they must roll? This would bring the stability I was seeking and help players gauge their prospective performance as the can bet on the median result of 11 which as become far more probable.
The divers checks would get easier to beat but as stated the PC wouldn't get this benefit on all of them and I think about giving the same advantage to important foes and nemesis.
With that in mind do you think it could works without upsetting the balance of the game to much? As in being able to use AP without buffing encounters and challenges.