Thursday, October 14, 2010

The Allure of 2d6

I ran another session of the Cold War game on Monday. Slightly weird session, bringing a few things to violent culmination, and also introducing the first real point of departure from real history. Previous disastrous events had happened in the shadow of real world disasters, allowing for a bit of sleight of hand that allowed things to keep from divergence. I'm pondering what impact that's going to have on things - on one hand I could probably smooth things over and keep to traditional history. On the other hand, I could embrace the divergence. It would be a bit of a weight off my shoulders and allow me to start bringing in the weirdness a little more hot and heavy. Tough call.

I also took a bit of a mechanical departure and switched to a 2d6 model for the session (added together, not d6-d6, as is sometimes a substitute for fudge dice). Blame it on the combination of Apocalypse World and the loveliness of the d6s that came out with the endgame celebration.

This is not the first time I've been bit by this particular bug. Endgame's previous dice were beautiful as well, and other games and celebrations that have offered commemorative dice have inspired me to think "Man, I need to do something with these very cool dice." The problem is that 2d6 is a harsh mistress.

Part of the problem is that in limiting myself to two dice I lose one of the better mechanical sliders for additive dice games - bonus and penalty dice. That removes PDQ from the table and leaves me with what is, frankly, a not terribly satisfying curve. But Apocalypse World does a pretty good job within that curve (up to 6 is failure, 7-9 is limited success, 10+ is a clear success) and I figured I'd give it a shot. The Cold War ladder is different than normal fate - it's just three tiers at +2, +4, and +6. The one +6 pretty much overwhelms the roll, but that's in keeping with expectations - the characters are pretty much James Bond with a focus on whatever that +6 is in. The +2 and +4 are a bit better than AW characters (who cap out at +3) but that's fine - I was skewing towards a little bit more success.

That was all well and good in theory, but it fell a little too flat in practice. It might have been a result of the specific dice that night, but things skewed even higher than I expected. That was inconvenient, but what it really did was highlight the thing that a 2d6 curve needed was the explicit outcomes of Apocalypse World. In their absence, it makes for a fairly uninteresting distribution of outcomes, especially partial successes. The detailed outcomes of AW (and the way they are explicitly designed to push play) are what make it sing. Which is to say, the dice and the outcomes are a much more atomic unit than I originally thought.

Now, it wasn't a total loss. It still worked, but if i do it again I'm more likely to go to a 3d6 based model. That's a bit more of a fun spread, and allows more tricks. It does mean leaving the 2d6 by the wayside again, but I'm sure I'll be back again.


  1. Rob, with Chimaera we're playing around with |d6-d6| which is showing some interesting flexibilities. This is d6-d6 but you always subtract the lower from the higher. This is very fast and intuitive and yields an interesting curve that peaks at 1 and tapers out to 5. It's especially tasty in opposed rolls, where the curve becomes -5 to 5.

  2. @Brad I remember looking at that curve and being really intrigued by it. I am super curious to see what you do with it, but you've also left that bit of math rattling around in my head.


    It just rattled some more. Must think upon this.

  3. I believe that the Time Lord RPG that came out years ago (using Doctor Who license) made use of |d6 - d6| for its system. The way it worked was that stats were rated from (usually) 3 to 7, and Difficulties were within the same range more or less. You would take the difference between your stat and the Difficulty, if your stat wasn't greater (because if it was greater, you didn't roll) and try to beat that difference using the d6-d6 roll.

    So if your stat was 6 and the Difficulty was 8, the difference was 2. You'd have to roll 3 or more on |d6 - d6| which wasn't terribly easy, but possible.

  4. My standard trick for bonus/penalty dice for 2d6 (or 3d6, actually) is the old Over the Edge rule. Penalties add a penalty die, then drop the highest die; bonuses add a bonus die, then drop the lowest die.

  5. @Bryant That is exactly the rule I love, but it requires carrying more than just two dice, and thus I shake my fist to the skies.

  6. @Brad: Sounds similar to Qin the Warring States, which does the same thing with d10s. And if your dice are different colors (as in Qin) you can also include a "which color is higher?" dimension in the result. (Again ref. Qin, whether the roll is "Yin-dominant" - black die higher - or Yang-dominant - white die higher.)

    What do you do with doubles? Treat them as a zero, or as some kind of special result?

  7. @Bryant That is exactly the rule I love, but it requires carrying more than just two dice

    I guess you could re-roll the lowest die for a bonus or the highest die for a penalty. I rarely find myself without a 3rd D6, though.

  8. You could use 3d6 drop the middle die, with penalty meaning drop the high die instead, and bonus meaning drop the low die.

    Instead of +2, +4, +6 you might consider +1,+2,+4 when using the Apocalypse World 6,7-9,10+ outcomes. Also, you're definitely right that the detailed lists are an important part of the AW approach.

  9. @Carl When you go 3d6, you also get the option of going Min-Mid-Max, which is just an elaboration on what you suggest, and which has some crazy fun properties too.

    All of which is to say that I might just have to accept that as fun as 2d6 look, that 3d6 workhorse is just too much the good choice.


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