There are a lot of different dice mechanics out there. Percentiles, roll under, roll over, pools, FUDGE dice, and variations for all of them.

I started out this game with a simple d20-roll-over-10 mechanic, but eventually realised that this led to a few unconsistencies. After some experiments and calculations with AnyDice, I settled on a pool mechanic. Thus, the basic mechanic for all rolls is the same:

You take as many dice as you have Advancements for a particular Base Skill and roll them. Any die that shows up a number that is on the upper range of the dice range (ie: 4, 5, or 6 on a six-sided dice. Or 3 or 4 on a four-sided one) is a Success. If you have equal or more successes than the stated difficulty, you win that roll.

Whenever the action you try to do involves damage (be it dealing it or healing wounds), the type of dice become important. They get chosen based on the skill or equipment used, and if you win your roll, the dice among your Successes that shows the highest number denotes the damage you do or heal. If that number shows up more than once – you got a critical success and you deal the appropriate multiple.

So, let’s look at an example:

Seamon the Sorcerous Sapper attempts to throw a fireball at a cave troll. He has four advancements on that particular skill, (two of them involve damage upgrades) so he throws 4d10 as his pool. He rolls the following numbers

3, 6, 4, 9

That means he has two Successes (he only needed one), and deals 9 points of damage to the troll (which is the highest number of his two Successes)

So, one roll figured out whether the action was successful or not, and what kind of damage it did. Simple and fast.