YARPS Success Tests

I haven't made nearly as much progress on YARPS as I would like (with being so close to shipping a major product release at work), but I have managed to spend a few nights crunching numbers and settling a few key design decisions. It's already clear that what will finally be YARPS will be quite different from my original thoughts, but that's okay; I really like the shape that it's taking. I've nearly finished designing the fighter class, and I'm happy to report that it's a fighter class I'd enjoy playing (which is saying something, as I don't generally like playing pure fighters). Hopefully I can post a preview later this week.

One of the decisions I made last week was to use 2D6 as the dice roll for competency and success tests. As you surely know (unless you've never role-played, in which case I have to ask, "Why are you here!?"), D&D and many other games use a D20 for the "core mechanic." I like 2D6 better because there are 36 possible outcomes instead of 20, with almost half as many possible end results (11). This, in turn, means two things: min and max rolls are less likely (nearly half as likely), and a +1 modifier applied to the end result is more significant (because there are nearly half the end results).

(There's also an interesting dice pool system that can be applied with 2D6, but that's the subject of a future 'blog post).

To illustrate the difference, imagine you're playing D&D and you need to roll a 20 to hit. Your character has a +1 modifier to hit. This means you have a 1 in 10 (10%) chance to hit. Adding another +1, for a total of +2, increases your odds to 3 in 20 (15% ). Each additional +1 will increase your chances by another 5%. That's helpful, but it means you need to start stacking bonuses before it's really meaningful, especially at high levels. Anyone who's played older editions of D&D for any length of time has experienced this.

Now let's pretend you're playing YARPS, and you need to hit an opponent with a DEF (defense) of 12 (the equivalent of D&D's 20). If you have a +1 to hit, your chances improve from 1 in 36 (3%) to 3 in 36 (8%). Add another +1, for +2 total, and your chances improve to 6 in 36 (17%). Each additional plus increases your chances along a normal curve. Whereas your chance only improves to 25% with +4 in D&D, your chance improves to 42% in YARPS.

And, because YARPS works against a normal curve, the effects of modifiers are even more striking for usual (that is, level-appropriate) rolls. Rolling a 10 in D&D with +1 gives you a 5% boost, from 50% to 55%. Rolling a 7 in YARPS (the nearest equivalent) with +1 gives you a 14% boost, from 58% to 72%.

What does all this mean, applied? It means that in YARPS, you'll really appreciate those +1 bonuses. It means that if you have the highest score for a given attribute, you will really stand out among your race. It means that a level 1 orc has only a prayer of defeating your level 10 PC, and your level 6 PC isn't going to fare well against that level 12 dragon. And It means that I don't have to inflate or stack bonuses (or have huge hit point pools) to achieve the sort of level disparity and character growth curve that I'm looking for.