Reflections on RPG Design: Skills the B/X Way

My most recent article, “Reflections on RPG Design: You Need Skills (Just Not That Many)”, was a rambling flow through different decisions that I made when designing an OSR/NSR-inspired 4E-principled homebrew.

(That article is here, if you want to read it: https://hephaistos.substack.com/p/reflections-on-rpg-design-you-need)

While I did my bare-minimum “due diligence” research for that article, I wound up spending quite a bit of time exposed to B/X’s skill system (see the article if your kneejerk reaction is “B/X doesn’t HAVE a skill system!”). Then I spent a lot of time looking at Lamentations of the Flame Princess’s distillation of it…

and I came to like it.

I know, I know.

So, I rebuilt “Materia Mundi” using LotFP’s “N-in-6” d6 skill system, ditching all my fancy “proficiency dice” rules.

And the more I carved out, the more a beautiful little system emerged.

I’m gonna shill that system to you now.

Skills and Abilities

One principle that I cannot let go of is, “abilities should contribute to your skills somehow”. This can get hard if your skill probability granularity is a D6. A +2 bonus is huge for a D6.

Luckily, there’s a pretty easy solution.

If you make sure that there are exactly 3 skills per Ability, then you can use the -3 to +3 Ability modifier to assign -1 or +1 to that many of that Ability’s skills — effectively “splitting up” the Ability’s modifier into chunks small enough for the skills to swallow without statistically choking on.

Okay, that metaphor got a little weird.

Anyway.

This means having 12 skills — Con and Str don’t really need skills, since Con is doing the whole hit dice thing, and Str is doing both attack throws and “feats of strength” (which, as a N-in-6 roll, look like a skill but aren’t — it already uses your whole Str mod in the base B/X rules, and it never adjusts based on level).

Many of the N-in-6 tasks are pretty clearly related, and I already did a lot of the consolidation work when building Materia Mundi’s original skill system. This rebuild affords me some nice opportunities — putting Medicine back under Intelligence, for example, and getting rid of Crafting as an independent skill — that I was already on-the-fence about.

Anyway, without further ado:

Twelve B/X Skills

Dexterity Skills

Acrobatics

This is the N-in-6 “Climb sheer surface” roll, which obviously belongs in Dex since it’s a Thief skill.

Finesse

This combines the N-in-6 “pick locks” roll with the N-in-6 “pick pockets” roll, both of which involve trained fine-motor control.

Stealth

This combines the N-in-6 “hide” roll with the N-in-6 “move silently” roll, both of which involve precise full-body control, precise awareness of your body's position and movement in space, and awareness of your environment.

Intelligence Skills

Arcana

This is an N-in-6 roll for maintaining concentration on a spell in adverse conditions, for brewing potions, for crafting magic items, for designing new spells, and for recognizing Weird Magic Shit.

Medicine

This is an N-in-6 roll for diagnosing and treating illnesses, poisons, and diseases through mundane means.

Lore

This is an N-in-6 roll for knowing various bits of in-universe knowledge that a character would reasonably know but a player might not, as well as a way to track literacy and extra language acquisition. It can also be used for various bits of navigation and pathfinding, especially the parts about reading maps, recognizing known landmarks or paths, and knowing which town or road is up ahead.

Wisdom Skills

Animal Ken

This is an N-in-6 roll for managing mounts, pack mules, animal companions, wild beasts, you name it.

Perception

This combines the N-in-6 “Listen at Door”, “Detect Traps”, and “Detect Secret Doors” rolls.

Survival

This combines all the N-in-6 “hunt”, “forage”, and “navigate” rolls, as well as giving Druids and Rangers something to do that’s analogous to Arcana for wizards (if you have those classes).

Charisma Skills

Charm

This is an N-in-6 roll for influencing an NPC’s Attitude.

Leadership

This is an N-in-6 roll for managing your minions, and can also track how many minions you can hire.

Wit

This is an N-in-6 roll for influencing an NPC’s behavior, given their current attitude.

The Mechanics

Okay, so here’s the deal:

Each of these skills has seven possible levels:

• Inept (0-in-6)

• 1-in-6

• 2-in-6

• 3-in-6

• 4-in-6

• 5-in-6

• Mastery (6-in-6)

By default, all twelve skills all start at 1-in-6.

If you have a positive ability modifier, that many skills linked to that ability start at 2-in-6, instead.

If you have a negative ability modifier, that many skills linked to that ability start at inept (0-in-6), instead.

If your class has any class skills, they each get a 1-point increase at level 1. At each level after level 1, you can either increase two class skills by 1 each, or increase one non-class skill by 1. (If you don’t have any class skills, you’re obviously doing the latter).

BOOM! Done. We have now linked skills to Abilities in a simple, fast way, without letting them overwhelm the D6 probability window and without doing any of that weird-ass “math” stuff.

So Who Gets Which Skills?

Splitting the skills between the classes is the next obvious step. You want certain classes to have “niche” skills that only they can do, so that everyone has a role to play.

Fighters

Fighters are pretty generic, and their niche is “I hit stuff with my axe”, so it’s pretty reasonable to just not give them any class skills. They can pick one of any skill to increase each level.

Thieves

Thieves obviously need to be the “skill monkeys” of the party. At minimum, they need all the Dex skills (Acrobatics, Finesse, and Stealth). They also obviously need Perception. For my games, I also give them Lore and Wit, to fit their role as the fast-talker and the treasure-hunter.

Magic-Users

Magic-Users obviously need Arcana, duh. Giving them Medicine and Lore, to round out the Intelligence skills, seems like the obvious choice. Giving them Finesse for all that finger-waggling somatic spell component stuff also seems right. Four skills seems like a good place to stop; we don’t want them challenging the Thief for skill versatility.

Cleric

Clerics seem like a good candidate for the Leadership skill, and maybe the Charm skill — if you spend most of your day convincing people to be nicer to each other, you better be pretty charming. Lore also seems like a good one, to reflect all that time spent studying religious texts and history books and philosophical treatise on the nature of free will or why gentiles can eat shrimp or whatever.

Other Classes

You’ll maybe notice that the Animal Ken and Survival skills haven’t got any love from any of the classes yet. Sure seems like a job for a Ranger or Druid class, doesn’t it?

(Or if you’re doing Race-as-Class, I suppose you can put them in the Elf class. Personally, I just have my Elf class be the Ranger or Druid class when I’m doing race-as-class, it just feels right somehow.) Anyway, whether you call it “Ranger” or “Elf”, the proper skills feel like all the Wisdom skills (Animal Ken, Perception, Survival), and then Stealth and Acrobatics, and maybe Medicine? That puts us at six skills, right on par with the Thief, so this is starting to sound like a Ranger class (or, again, an “Elf” if you wanna do race-as-class. I’m a blog post, not a cop.)

And now, on to a little diversion

Abilities and Saving Throws

Now that we’ve linked abilities to Skills, wouldn’t it be nice to give saving throws the same love? Luckily, each saving throw uses a d20, so just adding a full Ability modifier is perfectly kosher. In fact, standard B/X does exactly that, but it exclusively uses Wisdom for it.

Let’s see what happens if we go with the 5E “one save per Ability” idea, but using B/X’s saving throw system.

First, we need six saves instead of five, since we’ve got six abilities. The cool thing is, we can just turn “morale” into another save — making it a d20 instead of a 2d6 — which actually reduces rules from B/X instead of adding them!

So, let’s come up with some proper names for each of the six ability saving throws:

• Strength - Save vs. Knockdown or Paralysis

• Constitution - Save vs. Death, Poison, or Disease

• Intelligence - Save vs. Illusion or Confusion

• Dexterity - Save vs. Blast, Bolt, or Breath

• Wisdom - Save vs. Curse or Beguilement

• Charisma - Save vs. Fear or Despair

Hey, look at that! Six saves that make way more contextual sense than “save vs. rod or staff”. And each one linked to an Ability!

Class Levels and Saving Throws

While we’re at it, I have something to say about hit dice / class levels.

There should only be nine of them.

Yeah, you heard me. Level 9 should be the top end for humans and demi-humans. It’s the point where you stop gaining proper hit dice, and it’s a single-digit number so you can make the slot on your sheet for it smaller.

What? That matters sometimes!

Anyway, making L9 be the cap makes some other things pretty fun. The biggest is, you can have attack throws and saving throws go up one-to-one with level.

So saving throws can literally just be “15 - (level + ability modifier).”

If you want some classes to have better attacks and saves than others, you can have that be the good progression. The poor progression could be “15 - (level÷2 + ability modifier)”, and if you want something in-between (let’s call it “fair”), you could maybe do “15 - (level x ⅔ + ability modifier)”.

Then you give everyone Fair attack and save progressions by default, but maybe everyone gets Good saves in their prime requisite, fighters get Good attack throws, and wizards get Poor attack throws.