Thursday, November 22, 2012

Some Thoughts About the Target 20 Mechanic

I finally got a chance to play Stars Without Number, last night, with James Aulds. It was a lot of fun. Also had a chance to game with a bunch of people with whom I'd not gamed before. So, thanks to Eric, Gus, and Peter, as well. On a side note, playing SWN really made me want to try out Other Dust sometime really soon. So much potential fun there.

I've been meaning to play this game at some point, but haven't had the chance up until now. It gave me a chance to play with a few mechanics I'd not used before. One, which I may write about later, was using 2d6+Attribute Mod+Skill Level for skill checks. I like this a lot and may want to hack it in some way for DCC, later. The other, which I will write about today, is the "Target 20" mechanic for combat resolution. As stated in the rulebook:
Roll 1d20...
+ target’s Armor Class 18 [this is descending AC, btw]+ attacker’s Combat skill
+ attacker’s attribute modifier
+ attacker’s Attack Bonus
If the total is 20 or greater then the attack hits. A natural roll of 1 always misses, and a natural roll of 20 always hits.
So, for example, if I'm a warrior type character with skill in a 15 DEX and skill in Combat (Energy Weapons), but no other modifiers (e.g., Attack Bonus) attacks an opponent with AC 2, the sum of the d20 roll +2 AC +1 for DEX +1 for Skill  must equal 20.

In order for this to succeed, our warrior would need to get a 16. I really enjoyed using this mechanic. I'd heard about it a bunch of times while reading others' blogs, but I must confess that I had a hard time getting my head around it in the abstract. In play, it's intuitive and super quick and simple. As James Aulds said, it's easy-peasy.

I got to thinking, though, about whether it could be adapted to ascending armor class, without to conversion to descending. Unfortunately, I don't have sufficient ranks in Profession (Mathematician) to figure this out. In my head, I see it working like this:
Roll d20
- (minus) target's Armor Class [ascending]+ attacker’s Combat skill
+ attacker’s attribute modifier
+ attacker’s Attack Bonus
So, using the same equation, we get: d20 - 18 AC +1 for DEX +1 for Skill. A roll of 16 on the d20 gets us a total of... zero. Does this mean that the new target number for the mechanic is zero? I'm not certain that I've got this quite right in my mind. Does it work? ... Anyone? ... Anyone? ... Bueller? "Target Zero" does sound a bit sexier than "Target 20," I think, so there's that.

I also started thinking about other "Target" numbers that might allow for the use of other dice, like a Target 30 mechanic (or even Target 24) to allow use of my Zocchi dice, if I'm using this for DCC. I'm not sure this is worth doing, though, as it starts to muck about with the simplicity of the d20 roll. Plus, Zocchi dice are way too expensive, and not everyone uses them.

One could use this for DCC pretty easily. It wouldn't require a skill system. DCC already lets you add level to rolls. The type of roll for which you get this bonus depends on class (Warriors get it to hit, Magic Users and Clerics for spell checks, etc.). There's your "skill" portion of the equation, though it limits the "skill" to the specific profession. This might be problematic, but then we could just assume that the combination of background and class gives the character certain default skills, like is done in the Warhammer Fantasy RPG career system, then the individual characters' skillsets are pretty intuitive and flexible as well.

DCC also uses attribute modifiers, and these can be added as well, though they're potentially higher in DCC than in Stars Without Number (which sets a lower ceiling and floor on them).

DCC also allows for an attack bonus. Warriors and Dwarves benefit the most from this (as they use a variable "deed die" which grants a minimum of 1 to the roll), but all classes get attack bonus advancement with level progression.

So, using the Target Zero mechanic for DCC would work something like this for our Warrior, whom we shall call Randomus Examplesson.

Randomus Examplesson is a 1st level warrior with a 13 STR (+1 mod). He's about to bury an axe in the head of a target with 18 AC (ascending). We will assume that his Luck mod is zero for this example. So he would roll the following:
Roll d20
- (minus) target's Armor Class 18 [ascending]+ Deed Die (1d3)
+ Strength Modifier (+1)
+ Favored Weapon (Luck Modifier) (0)
Again, Randomus Examplesson would need to get somewhere between 14 and 16 on the d20 (variable due to the variability of the Deed Die) to hit Target Zero.

I kind of like it, but I'm just not sure it's worth doing it differently when the regular d20 mechanic of d20 + Deed Die + STR Mod + Favored Weapon Mod  >/= Target AC seems to work just fine, though maybe it would be easier to use the Target # system to "hide" monster AC stat from players. Not sure if the mechanic matters there, though.

Why would I adopt a Target # mechanic instead of just using the Roll vs. AC mechanic? Anybody have a good reason I should choose to use one or the other?


  1. Okay man, while I love your idea to use 2d6+stuff for skill resolution in DCC, I feel that at this point I have to point out that the Ascending AC system doesn't need a target number because the Ascending AC *IS* the target number. Trying to dress it up any other way is, I feel, making things more complicated than they need to be.

    On the topic of "Target 20," I first encountered this system a few months back when I first read Searchers of the Unknown and was shocked (shocked, I say!) by its simple elegance. It may not yield the same statistical results as traditional to-hit tables and THAC0 (you're 5% less likely to hit at level 1 than most OSR systems), but man is it easy to remember and figure out. To me, that's a huge part of the benefit of a system like this; if someone who's never played before can quickly and easily add the right stuff up and say with confidence "I hit it!" then you're in good shape.

  2. You're right. That's the real goal, anyway: Make sure your players don't have to think about the rules any more than necessary.