So, I finally published Materia Mundi, and its going reasonably well!
Since different people have different tastes in settings, Ive decided to split off the "core rule engine" into its own 50-page pdf (although at a 5.5"x8.5" page size, its really more like 25 pages).
Why You Should Care
E9 does what OSE does in only 25 pages of rules (or 50 half-pages), compared to OSE's 93 pages (once you cut out spell lists, magic item lists, and monster liste). It streamlines everything into a set of rules that fit entirely in a newbie player's head + a one-page character sheet, without abandoning any of B/X's original charms (six abilities, hit dice, classes and levels).
You can grab a print copy here: https://drivethrurpg.com/en/product/521001/
If you want the whole 280+ page Materia Mundi in print, it's here: https://drivethrurpg.com/en/product/533339/
So what is E9?
E9 is an OSR rule engine that is 95% compatible with OSE, Shadowdark, or similar B/X or AD&D1E derived systems; where it diverges, it has been optimized for speed and "keeping everyone in the moment". The core resolution mechanic has been optimized for "rulings not rules" without giving up all of the underlying structure that makes old-school B/X be B/X.
License
The entirety of E9 is released under the Creative Commons by-attribution Share-Alike license, v4. Feel free to build any game you want on top of these rules!
The Core Rules
At the bottom of the system are the familiar 6 abilities: Constitution, Strength, Dexterity, Intelligence, Wisdom, and Charisma, as well as classes, levels, and hit dice. The system uses these abilities in the familiar ways; roll 3d6-in-order, then convert to a -3 to +3 modifier following the familiar B/X mechanics.
Class and Level
All classes follow the same progression, going from level 1 to level 9. Classes fall into one of three "roles": fighters, experts, and magic-users.
At each level, you gain a hit die, which is d6+Con. Fighter classes gain an additional +2 bonus to each hit die, for a total of d6+con+2.
Attack and Saving Throws
E9 has six saving throws, which map to B/X's saves + a "morale" save. Each saving throw is linked to an ability, with a threshold of (15 - [level+ability]). Your two attack throw thresholds follow the same formula, so your melee attack throw is identical to your strength saving throw, and your ranged atrack throw is identical to your dexterity saving throw. This means that each time you gain a level, all your attack and saving throws go up by 1.
The six saving throws are:
- Con - save vs. Death (poison, disease, etc)
- Str - save vs Hold (paralysis, petrification, knockdown, etc)
- Dex - save vs Blast (cones, rays, bursts, etc)
- Int - save vs Trick (illusions, charm/beguilement, etc)
- Wis - save vs Curse (spells, weird magic, etc)
- Cha - save vs Fear (morale, emotional manipulation, etc)
Diffuculty System
Because the attack and saving throws are pre-computed, the system was designed to not slow the referee or player down with math. Instead, all rolls fall under one of five difficulties, determined diagetically by the referee based on the circumstances:
- Automatic - no roll required
- Easy - roll twice and choose the better roll
- Normal - roll one die as normal
- Hard - roll twice and choose the worse roll
- Impossible - dont bother rolling
Talents
Since this difficulty system allows the player and referee to quickly work out the details of a particular roll quickly in a "rulings over rules" fashion, and provide an "automatic/impossible" escape-hatch, a "thief skills" subsystem can be added in without it becoming a set of "win buttons" on your character sheet.
So, twelve talents were defined, to give experts a standardized base to work from. Each ability other than strength and constitution gets 3 talents. At character creation, all characters (even non-experts) define their base talents as follows:
- if your ability is +0, all your talents in that ability are 2-in-6.
- if your ability has a positive modifier, that many talents start at 3-in-6.
- if your ability has a negative modifier, that many talents start at 1-in-6.
Experts then get to increase one talent of their choice each level; other classes might increase a specific talent at a specific level to represent focused training (such as a wizard gaining Lore or Science training to represent the ability to understand magical phenomena).
The 12 talents are:
- Dex - Agility, Finesse, Stealth
- Int - Lore, Medicine, Science
- Wis - Alertness, Intuition, Survival
- Cha - Bearing, Charm, Wit
Like saves and attacks, talent checks use the core diffuculty system - the referee describes the situation, then the player describes their action, then the referee decides whether it succeeds automatically, fails due to impossibility, or has risk (at easy/normal/hard). Then if risk is involved, the referee decides which talent is appropriate and the player rolls at the difficulty assigned.
If you are the kind of die-hard that hates skills no matter how you're packaged, just use saving throws instead. I'm not a cop.
Armor and Weapons
Since attack throws are static, armor as AC cant work. So instead, armor provides "damage reduction":
- Light armor reduces weapon damage by 1
- Medium armor reduces weapon damage by 2
- Heavy armor reduces weapon damage by 3.
Weapons always do damage based on their size:
- Light weapons deal 1d6 damage
- Medium weapons deal 1d6+str damage when held one-handed, or 2d6 damage two-handed
- Heavy weapons deal 2d6+str damage.
Shields just make attacks harder (easy becomes normal, normal becomes hard).
Other Subsystems
It's got simplified rules for experience, encumbrance, exploration, travel, socialization, and combat; all the bases are covered.
Anyways, I hope people like it!