An Idea for One-Roll Combat for Percentile Systems

I mentioned previously that I have recently gotten ahold of the new Runequest II and have been quite favourably impressed.  The most notable "wow factor" is probably the Combat Maneuvers; I was impressed enough to be inspired to do something along those lines for Under the Dying Sun.   I reread the book again over the holiday weekend (note for non-Yanks: we celebrated our Thanksgiving holiday last Thursday, making it a four-day weekend for most) and found subtleties to the system that I hadn't see before.

But that never stops me from changing things up.  It's what I do.  The idea that popped into my head was to do a One-Roll Combat System, along the lines of the one I came up with for Dying Sun.  I call it one-roll in that "to hit" and "damage" are both factored into the same roll; there are frequently several rolls required in RQ so this term isn't completely accurate.  But good enough.  Oh yes, I do know that there is the thing called the One-Roll Engine.  It doesn't work for me.  It just doesn't, so don't suggest that I check that out. 

Before I present the idea, I think a bit of background maybe in order.  RQ's percentile system is a type of black-jack system, where you want to roll under your skill number, but still roll higher than the other guy.  It's only implemented sometimes, but it's what the core of the system is (or should be).  Thus, in an opposed contest of whatever sort, if both actors make their roll, whoever rolled the higher wins.  This means that having a higher skill value not only gives you a better chance of success (one is more likely to roll on or under 70% than 35%), but also a better chance to make the higher roll (a roll of 60 is a success for the guy with 70%; the guy with 35% can't beat that roll at all except in the slight chance of a critical hit).

Unfortunately for me, RQ has never implemented that core idea as elegantly as I would like.  This particularly irks me in the cases of critical successes, which are achieved not by rolling high, but by rolling low (10% or less or your base chance).  Is that a bad mechanic?  No.  But it's so aesthetically unpleasing and we all know how important that is to me.  So, in addition to making a one-roll, I also want to drop that "roll high except when you want to roll low" business.

That all said, here's the basic idea:

The tens-die tells you how much base damage you have done.

Our first guy from above has "Sword & Shield" at 70% and roll a 27; his base damage is 2.  Had it been 57, his base damage would be 5.

What I like about this idea is that it plays on the blackjack system: you want to roll under your skill, but as high as you can under that.  It also continues the hidden benefits of having a high skill as the more skilled guy can get better base damage than someone less skilled; if you only have a 35% in "Sword & Shield", you can never get more than 3 base damage.

In this system, each weapon would have some sort of damage modifier that works off of the base damage.  I don't know exactly how I would set-up the modifier: whether it is a multiple (as Dying Sun is for now (hint, hint)) or just a straight plus/minus.  Whatever it is, is doesn't involve rolling dice (since that would defeat the point of the whole exercise).

With this idea, the quality of the roll effects the quality of the success.  And frankly, you could leave it at that, but RQ has always had the idea of critical successes.  I have two thoughts on this, one simpler and one that does plays better with the RQII system.  The first idea is a simple critical hit/miss system:

A success that is a doubles, doubles the damage.  A failure that is doubles is a fumble.

So, back to our two foe men.  The guy with 35%, can get a critical success on rolls of 11, 22, and 33, with the resultant base damages of 2, 4, and 6 respectively.  His opponent with the 70% skill, gets a critical on rolls of 11, 22, 33, 44, 55, and 66.  On that later roll, he would do base damage of 12, which is pretty hot.    But if he had rolled 77, 88, or 99, he would have fumbled (and RQ has always had fun with fumbling).

I have to be honest, I find calculating 10% of a skill on the fly somewhat difficult.  Yes, that may be pathetic, but it is what it is.  So this idea makes me happier.  Plus, what we get again is that the higher the skill, the better the chance of getting a critical success, the better the quality of the critical successes, and the less chance of getting a fumble.  That later one pleases me as I have also never cared for RQ's fumble calculations either which is roll low, but not too low, but not too high either".

What we don't get here is a clear blackjack mechanic.  Does that matter?  I don't know; I kinda like this doubles thing.   But we also don't have Combat Maneuvers here, so one might change the idea so as to say that rolling doubles makes critical success and drop the doubling of damage thing as that is folded into the Maneuvers system.

Maybe once we finish this DC Adventures game, I'll try out RQII with these rules.