The general gist is attribute + skill, roll under on 2d20 (+ meta currency) to generate one or more successes.
Each game line has a different implementation of the above. From what I could tell of the 20 or so minutes I caught of the stream is that Dune is on the light-to-mid crunch of the existing 2d20 implementations.
That’s a fair point. We didn’t cover base system as there are already a lot of experienced 2D20 players out there. But its only fair of me to give you the basic idea as its pretty straight forward.
When you want to do something, you decide on a combination or two attributes from your character. This is usually a skill and something else depending on the system. In Conan it might be fighting and Strength, but in Star Trek it might be Security and Daring. In Dune we have a skill and a Drive.
Adding up these two attributes gives you the target number, usually something between 8-15 depending on the game.
Now, you get 2D20 to roll. If any dice rolls equal to or under the target number it is a success. If you roll a 1 it counts as two successes (a critical).
If you have a ‘Focus’ a specialty on a skill that applies, you get a critical if you roll under your skill on any dice.
So, lets take Star Trek. Your character is shooting a Klingon, and its a Security and Daring test. Your attribute ratings are Security (3) and Daring (8) so the target number is 11. You roll the 2D20 and get 2 and 12 for one success.
Now lets say you have a focus in phaser you can apply, so a roll of 3 or under is a critical, so you’d actually have got 2 successes for this test.
To achieve a success you need to equal the difficulty of the test, rated from 0-5. Now, as you can only get 4 successes with a very lucky roll on 2D20, this is where Momentum comes in. For every success you get past the required difficulty, you can add a point of momentum to your group pool. Momentum can be spent (in escalating cost) to buy more dice for your pool (among other things) up to a maximum of 5 dice.
This is where difficulty 0 rolls are so good as they let you scout out a scene and gather a little momentum, representing how doing your homework has granted you an edge in what you are trying to do. Momentum is spent a lot in 2D20 as buying more dice often yields more successes to replenish the pool. So its not a resource to be saved too carefully but spent with more enthusiasm.
There are a few more tweaks, and we’ll go into how Dune does it once the preorder is out, but that should give you the basic idea.
-They talked about at least two years of Dune books.
-Corebook and first years of release will describe the first book era.
-Preorder at the end of this week.
-Special dice sets, and other goodies as well.