The Viscosity Engine

Quad-Integrity Framework

In the Orion Colonies, your 'Health' isn't a single number. It is the synchronized bandwidth of your physical form, your mental processing, your social tethers, and your technical interface. When one fails, the others must compensate — or you begin to Drift.

The four attributes serve to enable and empower actions through skills, as well as function as damage sinks. They can be impaired through injury or effect, making the associated actions less likely to succeed, or at least succeed well.

PHYSICAL

The Vessel

The raw structural integrity of your biological body and its ability to exert kinetic force.

Narrative Focus: Strength, speed, athletic grace, and the grit to survive vacuum or high-G burns.
The Threshold: Determined by your Physical Attribute + the rating of your EVA suit or armor.
The Cost: If this wing is suppressed, your body fails. You become slow, prone to injury, and physically incapable of high-exertion tasks.
Key Skills: Ranged Combat, CQC, Athletics, Endurance, EVA.

MENTAL

The Processor

Your cognitive bandwidth, logical speed, and the capacity to remain calm under the pressure of the void.

Narrative Focus: Observation, tactical deduction, scientific insight, and neural stability.
The Threshold: Determined by your Mental Attribute + specialized neural shielding or focus-enhancing gear.
The Cost: If this wing is suppressed, your "OODA Loop" collapses. You drop in the Initiative Cycle and find it impossible to process complex data or make rapid decisions.
Key Skills: Science, Medicine, Investigation, Tactics, History.

SOCIAL

The Tether

Your connection to linear time and the shared humanity of your crew. This is your shield against "The Quiet."

Narrative Focus: Influence, empathy, leadership, and your psychological resistance to Relativistic Drift.
The Threshold: Determined by your Social Attribute, minus your accumulated Drift Marks.
The Cost: If this wing is suppressed, you dissociate. You lose the ability to lead or be helped by others, eventually leading to Social Death—where you are physically present but no longer "there."
Key Skills: Persuade, Command, Deception, Empathy, Relativism.

TECHNICAL

The Interface

Your ability to manipulate the machines, Substrates, and digital lattices that keep you alive.

Narrative Focus: Hardware repair, starship piloting, hacking, and deep-syncing with AI mainframes.
The Threshold: Determined by your Technical Attribute + the redundancy systems of your tools or console.
The Cost: If this wing is suppressed, the world glitches. Your gear jams more frequently, your piloting becomes erratic, and you risk neural feedback from the ship's systems.
Key Skills: Engineering, Piloting, Hacking, Salvage, Substrate-Sync.

The Viscosity Engine utilizes a 2d12 bell-curve to prioritize consistent, reliable performance over the wild swings of a single-die system. When you attempt a task, you roll 2d12 and add your relevant Attribute and Skill Rank, comparing the total against a spectrum of four success tiers: Fumble (2–10), Success at a Cost (11–15), Clean Success (16–21), and Critical Success (22+).

This "Triangular Distribution" ensures that specialists can depend on their expertise while making the "messy middle" where you succeed but face a narrative complication, which serves as the primary driver of tension. Tactical advantages are handled through Modular Advantage, where you roll additional dice and keep the highest two, mathematically insulating your character against failure without breaking the grounded reality of the setting.

If you think you've seen something like this before, you're thinking of Powered by the Apocalypse games, which this deviates from in several ways, but that pedigree is certainly evident if you know where to look.

The Mathematics of the Void

Predictability in an unpredictable universe.

Why 2d12?

The standard d20 is a "Flat Distribution"—you have a 5% chance of rolling a 1 and a 5% chance of rolling a 20. It's pure chaos. The Viscosity Engine's 2d12 creates a Triangular Distribution. You are most likely to roll a 13, and least likely to roll a 2 or 24.

The Result: Your character's bonuses (Attributes and Skills) act as a "Stabilizer," pushing your average roll into the Clean Success range.
The Edge: Advantage doesn't just give you a +5; it changes the shape of the curve, making Critical Successes a calculated outcome for specialists rather than a stroke of luck.

The d20 "Bounded Accuracy" Trap vs. High-Fidelity Scaling

In many modern d20 systems, the design philosophy relies on Bounded Accuracy. This keeps the "math of the world" within a narrow range (usually DC 10 to DC 30) so that even low-level threats remain relevant and high-level characters aren't untouchable. While this makes the game easy to run, it often creates a "Competency Blur" that can make characters feel less unique.

The 5% Binary

In a d20 system, every +1 bonus is a flat 5% increase in success. Because the die (1–20) has such a high range of variance compared to the static bonuses (usually +3 to +9), the swing of the dice matters more than the skill of the character. A world-class scholar with a +9 can still routinely lose a history check to a lucky bumbling warrior with a -1. This "swinginess" can undermine the narrative of a character’s hard-earned expertise.

The Narrow Ceiling

Because DC values are capped to keep the game "bounded," there is a ceiling on how much better you can actually get. If a Master Rogue and a Novice Thief both need to roll to pick a standard lock (DC 15), the gap in their success rate is rarely enough to make the Master feel "superhuman." The math intentionally keeps them in the same neighborhood.

How Viscosity Engine Fixes This

The Viscosity Engine uses a Bell Curve (2d12) and Attribute-Based Skill Caps to create "Deep Specialization."

Reliability over Luck: Because 2d12 clusters in the center, a character with a high bonus (+6) isn't just "more likely" to succeed; they are mathematically insulated from fumbling. Their "average" result is a Clean Success.
The Bandwidth Wall: By tying Skill Ranks to Attributes (The Bandwidth Law), we ensure that a character’s "Potential" (Attributes) and "Training" (Skills) are inextricably linked. You cannot be a world-class pilot if you don't have the mental processing power to handle the ship.
Meaningful Degrees: In d20, "Success by 1" and "Success by 10" often feel the same. In Viscosity, those degrees determine if you take Trauma, mark Fatigue, or trigger an Overclock.

The Takeaway: In a d20 system, you are often at the mercy of the "d20 Chaos Factor." In the Viscosity Engine, your character’s build acts as a stabilizer, making your specialized actions feel intentional, reliable, and distinctly yours.

Narrative Character Creation

In Asterism Rhapsody, character creation isn't a math problem—it’s a Dossier. Instead of rolling for stats, you build a narrative "history" by selecting four distinct Aspects that define your place in the Orion Colonies from a library of possibilities.

Lineage (The Foundation): Where do your genes come from? Are you Planet-born (heavy and hardy), Void-born (adapted to zero-G), or Synthetic (a silicon native)? This sets your biological baseline. Or don't choose one of these if you don't identify especially well with one of the lineages.
Background (The History): What is your relationship with time? Are you a Sleeper from the ARK-era waking up in a strange future, or a Drifter who has spent their life trading secrets across the stars? Maybe your character is just "normal" and doesn't really feel a draw to one of these - thats alright.
Career (The Groove): What do you actually do when the alarms go off? From Short-range Pilots to Gruff Mercenaries, your career provides the professional "muscle memory" that gives you a mechanical edge. Maybe you don't have a career, that's ok, too.
Generic Aspects (The Personality): Use "Adjective-Noun" tags like Lucky, Jaded, or Battle-hardened to fill the gaps. These represent your temperament and the scars you’ve collected. Complete your four aspects with any number of these.

Why It Works

Narrative First: You don't say "I have a +3 in Technical." You say "I’m a Void-born Tinkerer," and the math follows the story.
The Bandwidth Law: Your Attributes (P-M-S-T) are derived directly from these life choices. Your potential is a reflection of your past.
Instant Persona: By the time you’ve picked your four Aspects, you have a fully realized character with a history, a profession, and a unique outlook on the "Viscosity" of the universe.

This results in a high-fidelity "snapshot" of a human (or machine) struggling to stay tethered in a galaxy that wants to pull them apart.

In a typical Race, Class, and Skill system, character creation often feels like an engineering project where players work backward from a desired combat output. You choose a "Race" for its attribute modifiers, a "Class" for its damage-per-second potential, and "Skills" to plug mathematical holes. This structure encourages Power Gaming because the mechanics are siloed; your character is a collection of "stats" first and a person second. It creates a transactional relationship with the rules where the goal is to "solve" the build, often resulting in "optimised" characters who lack a cohesive soul or a reason to be in the world beyond their utility in a firefight.

Contrast this with our Narrative-First Aspect System, where the mechanics are the subtext of your life story. Instead of picking a "Class" to determine what you do, you choose Aspects like Sleeper or Jaded Mercenary to define who you’ve been. Every point in your P-M-S-T (Physical, Mental, Social, Technical) wings is a direct reflection of a lived history—your Technical skill isn't high because you "put points into it," but because you spent a decade as a Void-Born Tinkerer scavenging ARK-era derelicts. This shifts the focus from "winning the game" to "inhabiting the friction." When your stats are derived from your narrative "Dossier," your character's mechanical strengths and weaknesses become a set of poetic truths rather than just a tactical spread, ensuring that every roll of the dice feels like a continuation of a biography rather than a calculation of a combat stunt.