initiative/specs/025-display-initiative/data-model.md

Data Model: Display Initiative

Modified Entities

Creature (domain)

File: packages/domain/src/creature-types.ts

Add one new field to the Creature interface:

Field	Type	Description
initiativeProficiency	number	Proficiency multiplier for initiative (0, 1, or 2). Defaults to 0 when absent from bestiary data.

This field stores the raw multiplier from bestiary data. The actual initiative modifier is derived via the calculateInitiative function — not stored on the entity.

Initiative (derived value)

File: packages/domain/src/initiative.ts

Not a persisted entity — a computed result from a pure function.

Field	Type	Description
modifier	number	The initiative modifier: DEX mod + (proficiency multiplier × proficiency bonus)
passive	number	The passive initiative: 10 + modifier

New Functions

calculateInitiative (domain)

File: packages/domain/src/initiative.ts

Input:  { dexScore: number, cr: string, initiativeProficiency: number }
Output: { modifier: number, passive: number }

Pure function. No side effects. Uses existing proficiencyBonus(cr) helper.

formatInitiativeModifier (domain)

File: packages/domain/src/initiative.ts

Input:  modifier: number
Output: string (e.g., "+7", "−1", "+0")

Formats the modifier with explicit sign. Uses U+2212 (−) for negative values.

Modified Adapters

Bestiary Adapter

File: apps/web/src/adapters/bestiary-adapter.ts

• Add initiative?: { proficiency?: number } to RawMonster interface
• Parse m.initiative?.proficiency ?? 0 into Creature.initiativeProficiency

State Transitions

None. This feature is purely derived/display. No state mutations, no events, no persistence changes.