I was wondering if the creators (or anyone else) could comment on the process that went in to choosing 2d6 instead of d20 as the main mechanism. I’ve got a lot of affection for the d20 (as I’m sure many here do), so it pains me to leave it so neglected. I understand that the probabilities work out very differently for the two rolling methods (in particular, modifiers being nonlinear and offering diminishing returns) — is this the main reason to go with 2d6, or are there others? Has anybody explored using d20 with any success?
I was wondering if the creators (or anyone else) could comment on the process that went in to choosing 2d6 instead…
I was wondering if the creators (or anyone else) could comment on the process that went in to choosing 2d6 instead…
2d6 makes the attribute plusses much more significant, which feels better to me. I think with a d20 you’d have to rejigger the modifiers or accept a more random game.
As a GM, I’m definitely not looking for more Golden Opportunities. I get them frequently enough now.
well it is based on Apocalypse World wich uses 2d6 to great success. It is much more average in it’s range making the 7-9 result (the most interesting result) coming up most of the times.
It’s an Apocalypse World heritage.
Dungeon World is such an awesome rendition of what I always wanted D&D to be, but it is sad that the mighty d20 got lost along the way. At some level, D&D is d20s and d20s are D&D.
John Zo is right, though. Sometimes I’m tempted to switch from 2d6 to 2d8, but it would wreck the basic mechanic to lose the bell curve and switch to 1d20, I think no matter what you did with the thresholds for weak and strong hits (7-9 and 10+).
The bell curve on 2d6 means that, unmodified, you’re going to be getting 7-9 over 40% of the time. That would be equivalent to rolling a 6 to 14 on a D20.
It would be hard to keep that 40% sweet spot in a D20 system. Plus rolling 2 dice is more fun than rolling one (the windup, the pitch, and the noises involved with the process). Which is why I always roll my damage dice with my to-hit in D&D. 😉
“It’s from AW” is an appeal to authority; I was wondering what considerations went into the deciding to continue with this method. The only thing that I can’t see being replicated via a d20 are the nonlinear scaling of stat bonuses (even then, that could be simulated via tables, although this would be much more complicated). Again, just looking for insight as to the various pros / cons.
You don’t have to leave your d20 behind! You can always roll it as a damage die. 🙂
2d6 is the leanest mechanic for the job. it makes each step from -3 to +3 matter, and reduces the processing time from mechanic back to fiction.
That said if you want to use the d20 just map the probabilities of the 2d6 bell curve onto the d20
http://homepage.ntlworld.com/dice-play/GraphBellShaped.gif
As an aside, on appeals to authority: the people who make D&D continue to use the d20 because that’s what D&D has always used, not because it’s the best tool for the job. Not trying to pick a fight, just making an observation.
I’ll also just echo what everyone else is saying: 2d6+modifier ensures that the 7-9 range is the most common result, which is what makes the game what it is. At its core Dungeon World, like Apocalypse World, is a game about hard choices and the consequences of failure (or success). A d20 mechanic is less about that and more about modeling how hard it is to do something. That’s not what DW is about, so changing to a d20 is going to turn it into something it isn’t. If that’s okay with you, do it. Just be aware.
We considered the d20 a bit, but ended up with good ol’ 2d6 for a few reasons. Most of those have already been covered: easy to get the bell curve, existing moves, compatibility with other *W games.
We also thought about accessibility: while we knew we wanted some crazy dice, you only really need one each of those. The only die you need two of is the one that you can raid from Monopoly.
There’s also some D&D heritage there too. While I first played 2E and only really got into 3E, the idea of a d20 as the die for D&D hasn’t always been set in stone. 1- or 2-in-6 chances are common for Moldvay, for example. We didn’t feel like that particular die was essential to the concept.
Sage brought up the point I was going to: the dominance of 1d20 is very much a 3rd edition thing. Personally I never liked it; I’m at my best with bell curves and dice pools. 2d6 feels comfortable, and sometime I must try it with 4dF. 🙂
I’ve toyed with the idea of XdF, with +s and -s being spent on move-specific benefits and costs.
The other advantage for me not covered so far is I can’t do the probability of each of the three outcomes in my head at the table. I could and would always do the success probability immediately with a d20, but I’m happier that my choices more character based than probability based with 2d6.
However, you can map the probability of other dice on pretty easily, especially to a d12 where the mods have a similar effect.
World games rely on moves snowballing and helping generate drive and story. With a single die your chance to get any single number is equal – meaning you are less likely to get moves to snowball. Mapping zones onto a d20 will not produce the same results.
Running with a minimum of two dice gives you a much better statement on what you want your game to do (you can trust the curve much more sharply, and use that to play to the message your’e trying to send) – while still allowing for a critical success or failure. It’s deliberate design.
The point about Moldvay is actually a pretty good point (in addition to the probability / diminishing returns reasons). I guess it wasn’t until 3e that the d20 became all-powerful.
Still, I feel guilty neglecting the poor thing :-/. It’s served me so well.
2d6 has better averages for rolling 6’s and 7’s without modifiers, which is where all the interesting stuff happens. When your bonus to a roll tops out at like +3 or maybe +4, this keeps things interesting, while still making your bonus feel powerful.
D20 is purely random. You’re just as likely to get a 6 or a 3 as you are a 14 or a 17. This puts the power of the narrative in to the hands of a very fickle system.
Scott, the d20 is a fine and noble animal. You should definitely take good care of it and show it love and playtime. It just doesn’t have to get that every game in the D&D cosmos. 🙂
(Strong notional debt to this artwork by fellow gamer and swell weirdo Ursula Vernon: http://browse.deviantart.com/art/His-Mind-Raced-27304494 )