I have long felt that the standard six Ability Scores are a little meaningless in the BX rules. I do accept that this can level the playing field a bit, but why have numerical scores if they don’t change the game much?

I decided to expand the range of ability scores values from 3-18 (which always felt very arbitrary) to 1-20. Sure, 3-18 is still the rollable range, but between species modifiers, character advancement, and critical wounds, those scores now range from 1-20.

I decided to lean into the idea of a standard -4 to +4 ability modifier range, as this has significant impact on both D12 and D20 rolls, both of which play a big part in The McHack. I also spent a lot of time trying to spread those modifiers as evenly as possible across combat, task rolls, saving rolls, and spell casting ability, so that all the abilities have real relevance. For example, Wisdom actively impacts the Degree of spell a Priest can cast, as well as impacting Saves v Magic (SVM) rolls, and Charisma (long the ultimate dump-stat) now impacts Elf Spell Courts, as well as Tasks of influence, intimidation, etc.

Because ability scores are more important in The McHack, I was able to use that fact to help make Dwarves and Elves more divergent from Humans through the species ability modifiers. It bugged me that these species just seemed like “humans with infra vision.” I think this little mechanic goes some way to fixing that problem.

Lastly, I wanted Ability Scores to be dynamic, both positively as a PC levels-up, and negatively due to serious injury and the negative impact of arcane magic. I decided to allow players to increase one ability score by one point (though not the same score two levels in a row). While I toyed with the idea of making this increase a random roll, I liked the fact that choosing an ability to increase felt like a character leaning into areas they wanted to improve in, or that naturally increased due to the experience of carrying out the duties of their class.

I also love the idea that serious wounds really impacting ability scores. Sure, you can keep adventuring after losing an arm, but that should have real consequences, right?

One important side effect of making ability scores more impactful to actual game play is that one can affect meaningful change to the character’s effectiveness in the game just by altering one root statistic. There is no need to write or remember lists of impacts that, say, loosing an arm has on attack rolls, AC, tasks, etc. You only need to adjust the affected ability scores and let those scores filter down through the game as adjusted ability modifiers. Easy.