Arcane Game Lore

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Designing Out Loud – Ability Scores – part 2

In my last article, I mused a bit about the different ability score options and thoughts that have been floating around in my head.  In part two I’m going to discuss my ideas for the two different sets of ability scores and talk a bit about each one.  Maybe by the end of this I’ll have come to a decision.

What Have I Done?

So I have done a little bit of design on characteristics based on both of the two different skill systems that I’m considering.  These were done at completely separate times with out comparing one to the other.  Here’s what I have so far and my thoughts on them.

BRP/RuneQuest Style

RuneQuest 3rd edition ability score list, STR, CON, SIZ, DEX, INT, POW, and APP

The ability scores from RuneQuest 3rd edition

I jotted down the notes for this one at my twins’ Boy Scout summer camp this year.  I was up for a couple of days teaching the Astronomy merit badge and was working on gaming stuff during the day while they were off doing activities.

For this system I settled on eight ability scores, one more than RuneQuest uses:

  • Strength – physical power
  • Constitution – health and vigor
  • Stature – physical size (equivalent to RuneQuest’s Size ability score)
  • Dexterity – fine and gross motor skill
  • Appearance – physical attractiveness
  • Intelligence – brain power
  • Willpower – strength and force of character (equivalent to RuneQuest Power)
  • Wisdom – intuition, street smarts, awareness of surroundings (this is the extra ability score)

My original thoughts were to base these on 3d10 for the ability scores with 16-17 as median and a range from 3-30.  And then use scores above and below 15 to modify skills.  Why?  At some level it was completely arbitrary but based on a few considerations:

  • I’m considering basing the system completely off d10s like Star Frontiers.  So it had to be a multiple of d10′s
  • To couple with the skill system, the ability scores need to be relatively low so that there isn’t a lot of math involved in computing the skill modifiers.  i.e. I wanted simple +/- 1 instead of something like +/- 1 for every 5 points.
  • 3d10 gives a slightly more bell curvy shape than 2d10 which is just a pyramid.  So 3d10 will cluster toward the middle values of 16-17 more than 2d10 will cluster toward 11.
  • 2d10 gives a 2-20 range similar to RuneQuest’s 3-18 range and I wanted to be a little different.  This one is a pretty lame reason.

The more I’ve thought about this, I think that despite 2d10 be less bell curvy, a range up to 20 is really the way to go as it makes other mechanics that use the ability scores directly a little better (i.e. ability score x5 gives you something on the d100 scale).  Although an alternate, if I don’t want to limit to d10s, is to use 3d8 and get ranges from 3-24 and then ability scores x4 puts you on a percentile scale.  Something to consider.

Star Frontiers Style

Star Frontiers ability scores, STR, STA, DEX, RS, INT, LOG, PER, LDR

Ability Scores from Star Frontiers

The notes for this one are contained in a preliminary player’s book I started working up just a month or so before I started this series of blog posts.  In this case I basically used the exact same scores but I renamed a couple of them and I also decoupled their creation so that instead of being generated in pairs, they are each rolled individually.  The ability scores I ended up with are:

  • Strength – raw physical power
  • Stamina – endurance and constitution – this is the basis for the characters hit points
  • Dexterity – fine motor skills (shooting, manipulating objects, etc)
  • Quickness – gross motor skills (responding to sudden events i.e. while driving/flying, dodging blows, etc.)
  • Intelligence – brain power and ability to learn
  • Wisdom – awareness of surroundings, insight into interactions, etc.  It would also form the basis for power in psi abilities if I include them. (This is Star Frontiers Intuition ability score renamed.)
  • Charisma – appearance and likableness. (Star Frontiers’ Personality characteristic renamed.)
  • Leadership – bravado, moxie, chutzpah, and command presence all rolled into one.  This is how well you inspire others to do your will and follow your instructions.

Like in Star Frontiers you would generate the value for these ability scores by rolling d100 and consulting a table to determine the exact starting value.  Since a d100 gives an equal chance of any score, and we want things grouped a little more toward the median, just making the roll the score doesn’t work.  Instead, I generated a probability curve using the awesome Any Dice website that allows you to generate distributions for any combination of dice and modifiers.

I based the distribution off of 10d10-5 (so that the average was 50 and we got a nice bell curve).  I then looked at the probability ranges and generated a table that gives realistic probabilities of generating the range of ability scores I was interested in (namely 30 to 75).  I actually had to stretch out the tails just a little to make the table simpler but the distribution is close.  Here is what it looks like:

Die Roll











Ability Score











Of course with the resultant values being in 5 point increments, one might ask why I don’t just divide by 5 and go back to a 20 point scale since they are mathematically equivalent?  And who knows, I might.  But with the ability scores on the same range as a d100 it makes ability checks simpler:  just roll against the ability score and you’re done, no math.

Do we have a decision yet?

Not quite.  I’m still exploring ideas.  But I think I’m starting to lean more in one direction than the other.  And the more I look at it, the more I’m convinced that the choice for ability scores is very much coupled with the skill and experience system.  These form the core mechanics of the game and have to be developed in tandem.

As time goes on, I’m starting to feel more like I want to try my hand at the simpler Star Frontiers style skill system and therefore related ability scores.  Maybe that’s just because I’m lazy.  I know that system will be simpler, both to create from a game design stand point as well as simpler for character creation.  Or maybe it’s because I want something compatible with all the Star Frontiers stuff I’ve done over the past 30 years.

On the other hand, I love the crunch of RuneQuest’s skill system and the infinite variations its vocations can give to characters. But I’m a astronomer and computer programmer by training and experience.  I like numbers and math is a no-brainer for me so I don’t see the extra complexity as a negative.

So in the end I’ll probably create both systems.  The real question is which one first?

Thoughts, comments, or suggestions?  Leave a note in the comment section below.


Categorised as: Game Design

One Comment

  1. [...] thought I was done with this set of ruminations with part 2 but after finishing that post I had a thought:  Would it be possible to combine the two different [...]

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