Margin of Safety Draft

Lore: Bernal the Balance-Keeper, a humble halfling clerk of the Veridale Ledger Hall, noticed that risk-blinded adventurers filled local infirmaries almost as quickly as taverns. Drawing on actuarial treatises copied from the towering Oracle’s Arch and folk-scale brewing notes traded by traveling aether-beekeepers, Bernal devised a mild, inexpensive draught that steadies the hand and sharpens the mind just enough to weigh peril against profit. Casks of the draft soon spread along caravan routes; its faint abacus-tick became the unofficial heartbeat of accountants, quartermasters, and cautious explorers across Saṃsāra’s island nations.

Description: A squat clay bottle sealed with braided reed and wax. When unstoppered, whisper-thin glyphs of shifting numerals spiral up the neck before dissolving. The liquid is clear amber shot through with pale teal motes that drift like suspended grains of sand; each mote pops in a tiny shimmer when the brew is swirled. The flavor begins sweet—honey and dried peach—then narrows to a dry, chalk-tinged finish reminiscent of ledger dust.

Color: Translucent amber with teal effervescent flecks.

Stats

• Tier: 1
• Rarity: Common
• Type: Brew (consumable)
• Dose: Single bottle, 0 .5 lb / 0 .2 kg
• Cost: 10 gp in most ports; often bartered for an accurate set of voyage figures
• Activation: Drink (action)
• Duration: 1 hour; a Guide-Manager may extend to the full day or session if narrative pacing demands
• Cooldown: A body may safely benefit once per long rest; further doses within 8 hours confer no additional effect and taste progressively of copper

Passive Magic: While the sealed bottle is carried openly, soft clicks echo faintly from within, matching the bearer’s heartbeat. These ticks instill a quiet focus—granting a +1 bonus on simple arithmetic or tallying tasks performed by that bearer. The effect ceases if the bottle is concealed or handed away.

Active Magic (upon imbibing)

• Actuarial Insight – For the duration, the avatar gains advantage on any check that involves probability estimation, route planning, trap-impact forecasting, wagering odds, or other risk-assessment challenges.
• Expected-Value Recalculation – Once during the duration, immediately after rolling a die for an attack, skill, or saving throw, the imbiber may reroll that die and choose either result. This decision must be declared before outcomes are revealed. A second attempted use during the same duration automatically replaces the result with the lower value, reflecting over-analysis fatigue.
• Ledger-Balanced Mind – The drinker’s passive Mind’s Eye view of numeric data (prices, distances, troop counts, cargo weights) appears briefly overlaid in crisp, teal-tinted glyphs, easing inventory or tax assessments.
• Side Effect – The precise diction the draught encourages imposes a –1 penalty on Deception or spontaneous performance checks as the tongue turns to factual phrasing.

Tags: brew, consumable, actuarial, probability, insight, common, amber, honey-peach, focus, reroll, risk-management, numeric-glyphs, mental-clarity, ledger-craft, route-forecast, caution-brew, accountancy-aid

The draught circulates through many layers of commerce, each shaping its price and manner of exchange.

• In the counting-rooms of Veridale’s Ledger Hall, junior actuaries purchase sealed bottles directly from the Balance-Keeper’s cellar clerk. Transactions are conducted in neat stacks of ten gold pieces, each stack audited on the spot against a pocket abacus. A receipt, scribed in duplicate, records volume, batch number, and projected shelf life; copies are archived in fire-proof cabinets beside insurance annals.
• Along the Grand Caravan Way, roadside waystations operated by the Caravanserai of the Golden Ratio keep a single crate behind the cash-lock. Caravan guards settle in silver, typically eight gold pieces’ worth of mixed coins or trade bars, but the steward also accepts one verified ledger of route statistics—detailing distances, hazards, and tolls—as barter of equal value. Such ledgers are copied overnight, then bundled into the station’s growing route-analysis library.
• At coastal ports like Tidecalm, dockside quartermasters stock the brew for navigating officers. Sale occurs across reinforced teak counters: nine gold pieces per bottle, or six when the buyer prepays with a chart showing current drift patterns and risk tables for pirate sightings. Harbor inspectors supervise each exchange, stamping the bottle’s wax seal with the city’s spiral-shell sigil.
• Within the vaulted corridors of the Oracle’s Arch racing circuit, bookmakers offer the draft in exchange for ten brass betting tokens—equivalent to twelve gold pieces—just before dawn heats. The purchase registers the imbiber for an obligatory liability clause; tokens return to the bookmaker when wagers close, maintaining closed-loop accounting during the multiday air-ship rallies.
• In smaller market-towers of floating cities, bee-brewers hawk it from collapsible hex-pattern stalls. Prices fluctuate with altitude and current aether-wind strength: between six and eleven gold pieces. Buyers often sweeten the deal by supplying fresh risk-event anecdotes—accepted as “narrative premiums.” The brewer notes these tales in wax-leaf ledgers that travel with each swarm hive.
• Remote monasteries dedicated to the Geometry of Providence distill their own variant under license. Visitors may acquire a bottle by presenting a donation of forty accurate pages of local census or trade data; the monks assign that material a fixed worth of nine gold pieces. Payment in coin is politely redirected to the monastery’s relief funds before the draught is dispensed.
• Itinerant scrivener-bands wander subterranean megacities, trading copies for services. One bottle exchanges for the drafting of a hundred-line actuarial clause or for escort through an uncharted tunnel segment appraised at equal risk value—reckoned at roughly seven gold pieces on standard city scrip.

Roleplay in different environments:

• Vaults of Chronos (Ancient Ruins): In the dim corridors of a long-abandoned vault, corridors twist in fractal patterns and pressure plates lurk beneath dusty mosaic tiles. A cautious avatar uncorks the Margin-of-Safety Draft before stepping into the gloom.
  • Offense: Eyes flicker with teal-tinted numerals as the avatar traces a safe path toward arcane locks. When closing in on a sealed sarcophagus, the drinker invokes Expected-Value Recalculation to reroll a key “lock-crack” check, opening the tomb with surgical precision. Each readied strike against animated guardians is timed to strike weak joints the Mind’s Eye reveals in shimmering glyphic overlay.
  • Defense: Silhouetted runes hovering in the avatar’s vision warn of concealed glyph-runes and collapsing archways. As a hidden dart launcher whirs to life, the imbiber uses Actuarial Insight to dodge at the exact moment of trigger, slipping past poisoned bolts. When stumbling into a room rigged with spinning blades, the brew’s Advantage on probability checks allows the avatar to gauge blade timing, weaving between teeth in a silent dance.
• Desert Caravan Escort: Under scorching sun and among shifting dunes, a caravan guard rallies with a sip of amber brew before the first sand-whipped horizon appears.
  • Offense: Scanning distant silhouettes, the avatar mentally tallies caravan and bandit numbers in glowing ledger lines. When outlaw raiders burst from behind dunes, the drinker reallocates resources—ordering a small strike team to flank at the narrow choke point the Mind’s Eye highlights as highest yield. A well-timed volley uses Expected-Value Recalculation to ensure that the decisive crossbow bolt finds its mark.
  • Defense: The crate of draft bottles at saddle-bag height clicks softly like shifting beads, drawing uneasy glances from caravan hands. As scouts spy movement on the horizon, the imbiber grants advantage on hazard-spotting checks to the driver, who steers the lead camel along a safer ridge. When sandstorms swirl, the brew’s +1 bonus to basic navigation keeps the caravan on true course, avoiding deadly drift into open waste.
• Floating Market of Aetherfall: Beneath suspended spires and drifting barter-floats, merchants hawk exotic wares. An avatar seeking profitable deals embarks on a calculated spree.
  • Offense: Over a cup of mint-leaf tea sweetened with honeyed brew, the drinker’s ledger-sharp mind assesses each stall’s markup. Advantage on probability rolls allows precise estimation of real value; the avatar uses reroll on a Persuasion check when haggling for rare aether-woven silks, securing a 30 percent discount. Silver-tongued yet fact-driven numbers pepper conversation until the merchant concedes.
  • Defense: Twisting through crowded pontoons, the imbiber’s Mind’s Eye display outlines probable pickpocket blind-spots as shifting vapor trails. When a street-thief feigns a stumble, the avatar rerolls a Perception check to catch the deft fingers before a purse thief vanishes into the crowd. The soft clicks of the sealed bottle remind the avatar to keep coin-purse held close, curtailing deceitful hands.
• Zephyr Circuit Airship Race: At dawn, wind-scarred decks and humming engines creak under ballast. A navigator-pilot imbibes the draft before the signal gong.
  • Offense: Teal motes swirl in the navigator’s goggles as predictive trajectories of rival craft arc across the sky. Actuarial Insight grants advantage on complex piloting checks; when the signal flare fires, the pilot dives into a coiling thermocline at the perfect moment, overtaking a rival on the updraft’s crest. Once per heat, Expected-Value Recalculation rerolls a risky maneuver check to slip past a tight chasm of cyclones.
  • Defense: As competitors launch grappling hooks to jostle the hull, the imbiber’s Mind’s Eye projects likely grapple-point strengths. The pilot rerolls an Evasion check to twist clear of a hook at the last whisper of likelihood. Under sudden tail-wind shear, the brew’s +1 navigation bonus steadies course, preventing a tumble into the turbulent aether below.
• Siege of Ironkeep: On battered ramparts and scorched earth, defenders marshal stones and scalding oil. A siege-engine master tastes the draft from a brass flask.
  • Offense: Guard-tower vantage expands with flickering numeric overlays marking weak wall segments. Before unleashing a trebuchet salvo, the master uses Actuarial Insight to pinpoint the optimal angle and tension. A rerolled Siegecheck (via Expected-Value Recalculation) lands the first projectile squarely in a breached gate’s hinge, toppling the portcullis.
  • Defense: Beneath pounding engines, the imbiber’s Mind’s Eye highlights probable breaching points on the wall. When battering rams pound at the barbican, the draft grants advantage on structural-assessment rolls, guiding repair crews to reinforce arches before collapse. As siege towers press forward, rerolling a reaction check ensures timely oil-drench triggers, searing splintered wood at exactly the moment it reaches the crenellation.

In each setting, the Margin-of-Safety Draft becomes an extension of the avatar’s inner ledger, its soft clicks and teal glyphs weaving actuarial precision into every defensive posture and offensive thrust.

Perception of Activation:

• User’s Perspective
  • Sight: Teal-flecked motes swirl at the edges of vision, tracing faint numerical glyphs along walls and objects. A soft, translucent overlay of shifting ledger lines appears whenever the mind’s eye locks onto prices, distances, or hazard points.
  • Sound: A gentle, rhythmic clicking echoes in the ears—like tiny abacus beads clicking together in time with the heartbeat—growing quieter as focus sharpens.
  • Smell: The air fills with warm honey and dried peach, layered over a subtle tang of chalk dust that lingers beneath the sweetness.
  • Taste: An initial wave of honeyed sweetness yields to a dry, powdery finish reminiscent of aged ledger parchment.
  • Touch: A mild, comforting warmth blooms in the chest, radiating outward to tingle fingertips and the base of the skull, as if unseen hands are steadying the mind.
  • Extra-Sensory: Probability currents become tangible—faint ripples of chance flow around creatures and objects, felt as gentle pulsations against the mind’s eye, guiding decisions and revealing likely outcomes.
• Observer’s Perspective
  • Sight: The imbiber’s eyes gleam with a brief teal light; tiny motes drift around their head like suspended sparks. A subtle shimmer clings to their movements, as if the air itself is infused with numbered mist.
  • Sound: In quiet surroundings, one might hear a soft clicking from the bottle or ears—an unearthly echo like distant beads sliding together.
  • Smell: A warm, fruity aroma of honeyed peach wafts from the drinker, drawing curious glances.
  • Touch: Standing nearby, one can sense a gentle heat radiating from the drinker’s chest and shoulders, like a hearth’s glow beneath their robes.
  • Extra-Sensory: Those attuned to aetheric flows perceive a calm, ordered field around the imbiber—an aura of balanced probabilities that dampens chaotic magic and soothes frayed minds.
• Positives
  • Heightened clarity in numeric and risk-assessment tasks
  • Advantage on probability, planning, and hazard-spotting rolls
  • One reroll to shift fortune in critical moments
  • Subtle Mind’s Eye overlays guide strategic choices
  • A calm, balanced mental state that eases stress
• Negatives
  • Dry, chalky aftertaste that lingers on the tongue
  • Slight stiffness of speech, imposing a penalty on Deception or improv performance
  • Mild mental fatigue if attempted more than once per long rest
  • The teal shimmer may draw unwanted attention from those who mistrust divinatory magic

Margin-of-Safety Draft Brewing Recipe

• Materials Needed
  • Aetheric Spring Water – 2 liters
  • Volcanic Barley Malt – 2 handfuls
  • Sky-Wheat Honey – 1 cup
  • Dried Moon-Berries – a small pouch (≈50 g)
  • Fresh Mint Sprigs – 2
  • Teal-Crystal Dust – a pinch
  • Ledger Inkresidue – 1 drop
  • Clean Clay Bottles – 4 (500 ml each)
  • Braided Reed Stoppers – 4
• Tools Required
  • Copper Kettle with Stirring Spout
  • Wooden Fermentation Vat (3 L capacity)
  • Rune-Etched Stirring Rod
  • Fine-Mesh Cloth or Rune-Etched Filter
  • Hearth Fire or Magically Heated Stone
  • Wax and Seal Carving Tools
• Skill Requirements
  • Herbalist or Culinary Brewer Proficiency
  • Basic Hearth-Temperature Control
  • Minor Aether-Infuser Training
  • Numeromantic Infusion Knowledge
• Crafting Steps
  • Mash Preparation
    • Heat Aetheric Spring Water in the copper kettle to 60 °C.
    • Stir in Volcanic Barley Malt and Sky-Wheat Honey until fully dissolved.
  • Herbal and Berry Infusion
    • Add Dried Moon-Berries and Mint Sprigs to the mash.
    • Maintain at 60 °C for thirty minutes, stirring every five minutes with the rune-etched rod.
  • Cool and Prime
    • Remove from heat and cool the mixture to 25 °C.
    • Transfer to the wooden fermentation vat.
    • Stir in Teal-Crystal Dust and drip in the single drop of Ledger Inkresidue, speaking a short numeric-focus chant.
  • Fermentation
    • Seal the vat and place it in a designated safe area (guarded cellar).
    • At dawn and dusk for five consecutive days, open briefly to stir with the numeric chant, then reseal.
  • Straining and Bottling
    • After five days, strain the brew through the fine-mesh cloth or rune filter into a clean container.
    • Decant evenly into clay bottles.
  • Sealing and Aging
    • Seal each bottle with braided reed and wax, carving three shifting numeral glyphs into the wax.
    • Store bottles in a cool, somewhat safe alcove for two days to allow flavors and motes to settle.
  • Final Inspection
    • Unseal one test bottle—its motes should swirl faintly when swirled, and the aroma of honey-peach over chalk dust should be clear.
    • If all sensory checks pass, batch is ready for distribution.

Note: (Duration may be extended to the full day or session with GM approval.)

Chronicle of the Balance-Keeper’s Draught

In the age when ledgers still bore witness by candle-smoke and the walls of Veridale’s Hall were unscarred by time’s rot, there lived one Bernal of the Halfling Lineage, called Balance-Keeper among scribes. This being, small of stature yet vast in tally, did pore o’er scrolls of fate and fortune until his quill grew stiff and his fingers bent as old reed. ‘Twas in those long nights, when silence multiplied like stones in a heap, that Bernal beheld a whisper—an echo of numbers dancing upon the wind. And so he resolved to bind that murmur in vessel and draught.

He journeyed first to the Oracle’s Arch, its crystal curves humming with unspoken sums, and there borrowed a scrap of ledger-glyph inscribed by the Fates themselves. From desert caravans he bartered in silver for sky-wheat honey that glowed like dawn, and in moonlit groves he coaxed mint from earth with songs of steady calm. To these he added barley grown upon ash-stained fields, and dusted all with teal-crystal shards gleaned from a shattered star. Three times the barley boiled in aether-spring water, each time he stirred with a rod of runes while chanting half-remembered digits in a tongue grown fractured by time.

When first the brew settled, motes of light clustered like wary fireflies, and the scent of honey and ledger-dust filled the hush. Bernal tasted with trembling hope, and found his mind unerring in small reckonings: the weight of coin, the curve of path, the hazard hidden in humble twig. News of this miracle spread faster than caravels before the wind, and soon caravans bore casks of the Balance-Keeper’s Draught like reliquary across ocean and mountain.

Yet not all eyes deemed this gift benign. In candle-lit council, stern captains whispered of over-precise minds unfit for sudden peril; jealous apothecaries muttered that such clarity might topple markets built on chance. A single cask vanished from the Hall one storm-tossed night, taken by stealth to sea-borne brigands who prized folly’s gleam. They drank deep as thunder rolled, only to miscount the hours ‘til dawn and flounder upon reefs thought clear.

Healed by the dawn’s salt mist, those brigands returned the empty vessel and begged forgiveness, for the draught had shown them ruin before their eyes—and still they heeded not. Bernal then bound the recipe in two tongues—one of halfling care, the other of ancient cipher—to guard against both greed and misuse. He placed it in a locked chest beneath the caravanserai of the Golden Ratio, sealed by wax carved with triple numerals, and declared that none may imbibe twice ere the sun be long spent.

Through ages hence, travellers still speak of the Balance-Keeper’s Draught with reverence and caution. Some say that a single sip can save a merchant’s life by weighting dangers as gold, while others claim its echoing clicks may summon auditors from the beyond. Whether borne upon desert sands or afloat on Aetherfall’s floating spires, the draught endures as testament that every risk, once measured, may bend to mortal will—so long as the heart does not outcount its wisdom.

Moral of the story: Even the smallest measure of caution, weighed true, may guard against the greatest hazard.

Suggested conversions to other systems:

Call of Cthulhu (7th Edition)

Margin-of-Safety Draft

• Type: Consumable (Common)
• Effect: When imbibed, grant a +20 % bonus to any Luck, Spot Hidden, or Library Use roll for 1 hour. Once during that hour, you may reroll one failed roll of those skills and choose the better result.
• Side Effect: While under the draft’s effects, suffer a –10 % penalty to all Persuade and Fast Talk rolls.
• Limit: Only one dose can be safely consumed per 24 hours.

Blades in the Dark (Tier 1 Common Downtime Elixir)

Balance-Keeper’s Elixir

• Effect (1 effect): Add +1 d to a single action roll involving planning, scouting, or leveraging resources (for example, Study, Survey, or Sway).
• Aftermath: Immediately suffer 1 stress. If the elixir was used to boost a Sway roll (deception), suffer 2 stress instead.
• Availability: One elixir may be carried into each Score.

Dungeons & Dragons 5th Edition

Margin-of-Safety Draught

• Potion, common
• When you drink this potion, for 1 hour you gain:
  • Advantage on Intelligence (Investigation), Wisdom (Perception), and any ability checks made to assess hazards or calculate risk.
  • A special Reaction: once during the hour, you can reroll one failed ability check or saving throw; you must use the new roll.
• Drawback: You have disadvantage on Deception checks for the duration.
• Consumption: The potion’s magic is expended on use; you cannot benefit from another Margin-of-Safety Draught until after a long rest.

Knave

Draught of Balanced Odds

• Type: Consumable (Common)
• Bonus: Add +1 d6 to one Action Roll that involves planning, risk assessment, or avoiding hazards.
• Reroll: Once before the end of the current scene, you may reroll any single Action Roll (of any type) and use the second result.
• Penalty: Suffer a –1 penalty to any Action Roll made to deceive or mislead others.
• Duration: Effects last until the scene concludes.

Fate Core

Draft of Balanced Calculus

• Type: One-Use Consumable
• Aspects:
  • Temporary Aspect Balanced Calculations (Free invoke; one use this scene)
• Stunt:
  • Calculated Clarity (requires Balanced Calculations): Once per session, spend a Fate point to reroll any single roll involving planning, forecasting, or hazard avoidance. You must accept the new result.
• Drawback:
  • Sober Precision – While under the brew’s effect, you take a –2 penalty on Deception and Rapport approaches.
• Acquisition: Single dose; GM may assign a Refresh cost of 0–1 to place in a character’s possessions.

Numenera & Cypher System

Tonic of Calculated Odds

• Type: Consumable (Single-Use)
• Level: 1
• Effect: You gain a +2 bonus to task rolls involving risk assessment, route-planning, trap-spotting, or probability judgments for the remainder of the current scene. Once before the effect ends, you may reroll one task roll and must keep the second result.
• Drawback: You take a –2 penalty to Deception or Stealth rolls until the effect ends, as your speech and movements become overly precise.
• Cost: Standard cypher cost (GM’s discretion), typically 10 ish credits or equivalent barter.

Pathfinder Second Edition

Margin-of-Safety Potion

• Item 1; Price 10 gp; Bulk L
• Usage: Consume (2 actions)
• Traits: Alchemical, Consumable, Common, Mental
• Effect: For 1 hour, you gain a +1 circumstance bonus on checks to Assess Risk (any skill check made to plan, forecast, spot hazards, or navigate). Once during that hour, you can reroll one failed check that benefits from this bonus; you must use the new result.
• Drawback: You take a –1 circumstance penalty to Deception checks for the duration, as your speech turns overly factual.
• Craft Requirements: Alchemy—expert; key ingredients include teal-crystal dust and ledger-ink residue.

Savage Worlds Adventure Edition

Ledger’s Edge Brew

• Type: Consumable, Common
• Effect: The imbiber gains a +2 bonus to Smarts and Spirit Trait rolls made for planning, risk assessment, or detecting hazards until the end of the next scene or up to 1 hour (GM’s choice). Once during this period, you may reroll any Trait roll (must take the second result).
• Drawback: You suffer a –1 penalty to Charisma-based Trait rolls involving Bluff or Persuasion for the duration, due to overly cautious phrasing.
• Cost: 10 gp (or negotiable trade in accurate risk-event anecdotes).

Shadowrun Sixth Edition – Draft of Balanced Odds

• Type: Chem (Rating 1, Consumable)
• Availability: 4 (Street)  Cost: 150 ¥
• Activation: Complex Action (ingest)
• Duration: 1 hour + 1 Complex Action
• Effects:
  • +2 dice to all Logic and Intuition tests for tasks involving planning, ambush detection, trap-spotting, or route assessment.
  • Once per dose, immediately after failing a Logic or Intuition test, you may reroll that test and take the new result. If the reroll also fails, suffer –2 dice to all tests for the remainder of the duration.
• Side Effect: –1 dice to Charisma-based tests for the duration as speech becomes overly precise.
• Chem Formulation Requirement: Conjuring 3 or Alchemy 3  Toxicity: 1

Starfinder Roleplaying Game – Calibrated Navigator’s Draught

• Type: Consumable (Drug)  Level 1  Price: 50 credits
• Activation: Standard Action (drink)
• Usage: Single dose
• Duration: 1 minute
• Effects:
  • +2 morale bonus to Perception and Profession (Navigator) checks for the duration.
  • Once during the duration, you may reroll any single d20 roll related to planning, navigation, or hazard avoidance; you must use the new result.
• Drawback: –2 penalty to Bluff checks for the duration as speech turns clinical.
• Preparation: Requires Medical 1 or Engineering 1

Traveller (Mongoose 2nd Edition) – Elixir of Weighted Odds

• Type: Chems (Consumable)
• Availability: Common  Cost: 30 credits
• Activation: Immediate (ingest)
• Duration: 1 hour
• Effect:
  • +2 bonus to Intelligence checks and to skill checks involving navigation, survival, engineering or any planning-based task.
  • Once per dose, after failing an applicable skill check, you may reroll that check and take the new result. If the reroll also fails, no further rerolls.
• Side Effect: Addiction risk (Endurance + Willpower vs. TN 12) if used more than once per 24 hours.
• Preparation: Chemcrafter 2

Warhammer Fantasy Roleplay Fourth Edition – Potion of Calculated Risks

• Rarity: Common  Price: 1 gc
• Activation: Drinking the potion (Action)
• Duration: 1 hour or until the end of the current encounter
• Effects:
  • +10 % bonus to Fellowship Tests made to gauge danger, negotiate tactics, or rally allies.
  • +10 % bonus to Perception and Wits Tests for spotting traps, structural weaknesses, or enemy movements.
  • Once per duration, you may immediately reroll a failed Fellowship, Perception, or Wits Test and use the second result; if that roll also fails, suffer 1 level of Fatigue.
• Drawback: –10 % penalty to Deceive Tests as language grows excessively literal.
• Contamination: 1 (roll after brewing to determine potion stability)