Recently I have considered replacing the d20 roll with the 3d6 roll, at least for a few sessions to see how it feels. This will be for a 4E game and will come with a few house rules necessary for this, like increasing threat ranges to similar percentiles, and making abilities that grant rerolls give additional dice to the pull (so oath of enmity means you roll 4d6 and ignore the lowest die, and if you get a second reroll you roll 5d6 and ignore the two lowest dices etc.). I understand the basic arguments about it, that it decreases randomness, may decrease combat speed because it is a more complicated process, and heck requires a lot of d6 around and I want to give it a try. Does anyone have any experience using 3d6 in place of the d20? How much does it truly affect gameplay? Any feedback is welcome.