Game Fanatic’s Log, Addendum 2019-09-08

Posted: 2019-09-08
Word Count: 1485
Tags: astral brp d100 magic-world openquest paranormality rpg

After a couple of days’ thought, I’ve changed my list of prospective homebrew RPGs from last time:


The basic premise remains the same: “PCs explore the Astral Plane.” Likewise, I’m still wrestling with my biggest obstacle:

this is an “embeddable” game, i.e. someone playing some other RPG can Scheherezade into [Astral] to represent their main characters. […] mechanics should be simple enough that anyone can grok them immediately […]

For a while I was assuming either 2d6 or d6 vs. d6, since the humble d6 is pretty ubiquitous. What if, however, I only require a small pool (5-7) of even-sided dice. That means our hypothetical “anyone” only needs 5 six-siders, a set of generic ten-siders, a set of custom Vampire: The Masquerade dice, a set of fancy Space 1889 or old school Ubiquity dice, or a standard polyhedral set. Probabilities for minimum number of success for number of dice look like this:

≥1 ≥2 ≥3 ≥4 ≥5 ≥6
1D : 50.00% :
2D : 75.00% : 25.00% :
3D : 87.50% : 50.00% : 12.50% :
4D : 93.75% : 68.75% : 31.25% : 6.25% :
5D : 96.88% : 81.25% : 50.00% : 18.75% : 3.12% :
6D : 98.44% : 89.06% : 65.62% : 34.38% : 10.94% : 1.56%
7d : 99.22% : 93.75% : 77.34% : 50.00% : 22.66% : 6.25%

My earlier notes rated abilities on a scale from 1 to 5; instead of modifiers to 2d6, that could just be a number of dice. NPC abilities were rated on the same scale; this could be the number of successes needed, the number of dice to take away (as in “Third System”), or both in some sensible combination. (Requiring successes reduce probabilities more than taking them away.)

(Or I could just write rules to use opposed d8s, d10s, or d12s instead of d6s.)


With the addition of “Quest World”, it’s more obvious that Paranormality needs to be a setting and rules for paranormal abilities written for one system and easily ported to others. Candidate “first systems” include:

Or else it uses mechanics that nobody else does and therefore won’t conflict with any other systems, like playing cards. Zener cards? Nope, this is getting silly.

“Quest World”

Both as a name and as a concept, “Quest World” is a mashup of OpenQuest, Mongoose’s OGL RuneQuest knockoff made usable, and Magic World (quickstart), Chaosium’s now out-of-print Stormbringer / Elric! RPG with the Michael Moorcock references filed off. It’s not surprising, since OpenQuest borrowed heavily from Stormbringer. Stuff I’d like to keep from each includes:

Other d100 games provide techniques worth stealing.

Letting Dice Do The Math

In Call of Cthulhu 7th Edition, a character can have “advantage” (or “disadvantage”) on a skill test. On that test the player rolls an extra tens dice (or more?) and uses the best (or worst) result. This mechanic lets the dice do the math, unlike adding or subtracting modifiers or dividing the bace percentage.

While CoC7 uses this mechanic sparingly, this method introduces bonuses and penalties more quickly and easily than adding or subtracting modifiers to the base percentage or dividing the base percentage by some difficulty factor.

Exchange-Based Combat and Sorting Tests

CoC7 introduced “Hard” and “Extreme” levels, which are 1/2 and 1/5 of the “normal” value of a skill. Character sheets have space for all three values, for convenience. They do double duty as modifiers for task difficulty and bands for degree of success. In unopposed rolls, the GM can simply state a particular task is Hard or Extreme, e.g. questioning an especially hostile witness. During close combat, instead of RuneQuest’s Attack-Parry-Riposte-Parry cycle, each party makes one Unarmed or weapon skill roll; if an attacker gains a greater level of success than their intended target, the attacker hits. Tied levels of success go to whoever rolled higher on the dice, although in that case both sides get at least a little scuffed up.

In contrast OpenQuest only defines Critical Successes and Fumbles. If a die result is ≤ 1/10th of the target number, dropping fractions, it’s a critical success. That’s easy to calculate: 1/10 of 52% is 5, 1/10 of 106% is 10, etc. If the result on the dice is 00, the result is a Fumble and bad things happen.

Success bands may require more bookkeeping than they’re worth, and it’s hard to see how bonus and penalty dice apply. Another technique I’ve heard of, however, is to throw a separate d10 to denote degree of success or failure.1 The percentile dice merely decide whether a test succeeds or fails. Using this die to perform Normal/Hard/Extreme math – probabilities work out practically the same – might mean that any success or failure is Normal when the Degree Die is 1-5, Hard when the Degree Die is 6-8, and Extreme when the Degree Die is 9 or 0. Critical Successes and Fumbles occur when percentiles read 01 or (1)00, and the Degree Die is ignored.

Grand Unified Magic Rules?

Finally for “Quest World” I’d like to overhaul and streamline how magic works. One of the RuneQuest family’s greatest strengths and greatest annoyances is that it’s easy to graft on a new magic system. I’ll defer a complete explanation to another post, because long explanation is long. Generally, though, I’d like to build complementary mechanisms that influence the feel of a particular magician’s magic without creating wholly incompatible systems.

Some possible ideas:

  1. Quick Magic: The combined magic system would resemble OpenQuest Battle Magic and Basic Roleplaying / Magic World’s Sorcery. each character would learn a repetoire of “spells”, and expend Magic Points to cast them. Confusingly, OpenQuest (and various RuneQuest editions) have their own systems called “Sorcery”, typically on augmenting and combining weak spells through “manipulation”. Ideally one could combine both themes:

    • simple spells with small, well-defined effects,
    • combined and augmented with metamagical techniques.
  2. Improvised Magic: While RuneQuest: Roleplaying in Glorantha retains a form of “Spirit Magic” that’s a cousin to OQ’s Battle Magic. it overhauled its more powerful magics in a way that resembles the noun-verb form of magic in Ars Magica. Rune Priests and Rune Lords base their Rune Magic on their “alignment” with various Runes and the gods who embody them. Sorcerers combine Runes with Techniques and then boost their range, duration, intensity, etc. Taking this approach might mean sorcerers initially improvise magical effects from fundamental principles and then rehearse them them as “spells” for speed and reliability. Mage: The Awakening and its predecessor did something similar, inspired by the aforementioned Ars Magica.

  3. Ceremonial Magic: Sorcery would resemble the more freeform rules from Barbarians of Lemuria. The sorcerer (player) decides what effect they want, the GM decides on a coarse-grained power level using some straightforward critera, and the sorcerer and GM decide what restrictions the spell has: time to research before casting, required materials, lengthy casting time, restrictions on time and place it could be cast, etc. The GM and players can compile previously “researched” spells, but theoretically a sorcerer with enough resources could do anything. This method biases magic against “combat magic” and toward long rituals, but in my view that’s a feature, not a bug.

  4. Magical Talents: Some magicians might wield something akin to the skill-based magic systems of Mythras, or the Magic and Psychic Powers from the BRP Big Gold Book. That is, some forms of magic are as simple as making a skill roll or performing a set of actions, the way mundanes exercise their special if more explicable abilities. Some abilities might borrow ideas from the BRP Super Powers section or Superworld. Improvised and freeform magic have some definite appeal, but certain concepts may require well-defined powers.

At the end I’d like more than a catalogue of spells. I’d like rough guidelines for creating spells, such as:

  1. I think the game was Chivalry and Sorcery↩︎