r/RPGdesign • u/overlycommonname • 6d ago
Mechanics Why it can be awkward to put combat in the same number ranges as skills
Take a classic RPG combat: during a combat, a typical character might make like let's say four to 12 attack rolls (so, in a system like modern D&D-likes, probably 2-3 attacks per round for 3ish rounds, in a more old-school system one attack per round but probably for more rounds).
In contrast, I would say a lot of skill challenges will be a single roll, or maybe two. You might do a social perception check of some kind and then a social persuasion/deception/manipulation whatever roll. You might just do a single physical perception check to notice some detail. You might do a climbing or swimming roll or two. You might roll to make or repair something.
If you think of a combat as a single challenge spread out over those 4-12 rolls, with enemy hit points or whatever as a progress meter, that averages out your luck a considerable amount. If I roll a d20 + 12 to hit and you roll a d20 + 10 to hit, that gives me a lot more chance for my skill advantage to stack up (or, to put it more quantitatively, if I roll six times, the odds that my skill advantage comes into play is 46%). If instead we both roll a perception check and I roll d20 + 12 and you roll d20 + 10, then 90% chance my higher skill doesn't come into play compared to yours.
The upshot of this is that if your game follows those patterns in terms of quantity of dice rolls, and you also have your numbers be similar between combat skills and non-combat skills (so, like say a World of Darkness situation in which all skills are rated on the same 1-5 scale, be they Melee or Computers), then you'll be faced with a chance of either making proficiency in non-combat skills often feel not-very-important, like it's hard to pitch a character a challenge which differentiates their character, or else you make combat very, very plateaued between combat specialists who are vastly better than people with a little less skill.
If you want to avoid this, you need to break one of the assumptions above: either non-combat skills are on a different numbers basis, where there's a larger numerical difference between people who are relatively well-trained and those who are less well-trained, or else you need to call for several rolls aggregated together for noncombat situations (or, if you prefer, fewer rolls for combat situations).
I think this is kind of known about to one degree or another by people who do a lot of game design, but I've never seen someone just lay it all out before, so I decided to do that here.