Content Patterns and Consistency

Use the narrowest existing type that fits reusable content. Investigators store playable characters; Creatures store threats; Weapons, Armor, and Items store canonical equipment; Markdown rules store procedures; Scripts store repeatable checks; Locations and Lore store setting context.

A data entry should be useful without becoming a second rules page. Put reusable numbers on the entry and adjudication procedures in rules text. References should point to canonical entries rather than copying statistics.

Canonical conventions

• Percentile checks: 01 Critical, one-fifth Extreme, one-half Hard, full target Regular; fumble 96–00 below 50 and 100 at 50+.
• Derived values: HP floor((CON + SIZ) ÷ 10); Maximum Sanity 99 − Cthulhu Mythos; starting Sanity POW capped by that maximum; MP floor(POW ÷ 5); Luck POW × 2; Initiative and Dodge DEX × 2.
• Combat: one action and movement; critical attacks maximize damage plus damage bonus and ignore ordinary armor; Extreme maximizes weapon damage; armor is flat and non-stacking.
• Wounds: half-max HP from one hit is a Major Wound; 0 HP bleeds 1 HP per round; death is negative CON HP.

Prompts for item art

Item illustrations should function as clear inventory icons, not as scenes. The item is the subject: center it, show it fully, and remove every supporting object that could make the image read as an illustration of a location or action. Use a plain, restrained background so the image remains legible at thumbnail size. Do not place hands, furniture, documents, rooms, landscapes, candles, tools, or other props around the item unless the item itself requires an internal component to be visible.

Use this prompt pattern for new equipment and other small props:

Inventory icon of a single [ITEM NAME] only, centered, isolated, fully visible, plain muted sepia background. No [LIKELY DISTRACTIONS], props, scenery, or other objects. Painterly Lovecraftian pulp RPG art, clear silhouette, vintage print texture, restrained charcoal and ink-black shadows with subtle sickly green and blood-red accents, no readable text, logo, watermark, or gore.

For example, the camera prompt used for the equipment set was:

Inventory icon of a single vintage 1920s bellows camera only, centered, isolated, fully visible, plain muted sepia background. No table, hands, props, scenery, or other objects. Painterly Lovecraftian pulp RPG art, clear silhouette, vintage print texture, no text, logo, watermark, or gore.

Keep the negative instruction specific to the item. A prayer book should exclude a chapel and candles; a lantern should exclude a room or floor; a rope should exclude hooks, hands, and warehouse scenery. If an item contains meaningful parts—such as a lockpick case with picks or a folder containing clippings—those parts may appear as part of the item, but they should not become a separate still life. Regenerate an image when the result emphasizes the setting more than the equipment.

Before publishing, verify that numbers fit their scale, success/failure/fumble outcomes are meaningful, derived values are not duplicated, references resolve, and important clues have more than one route. When a rule and an entry disagree, resolve the duplication at the source of truth.