gamedev-the-steward/docs/SIMULATION_DEFINITIONS.md

The Steward — Simulation Definitions

Purpose

Stable IDs and immutable definitions now form the vocabulary shared by simulation state, systems, world adapters, scenes, tests, and future save migrations.

SimulationIds is the canonical source for code-facing StringName IDs. ActionDefinition and ProfessionDefinition are editor-readable custom resources. SimulationDefinitions loads, resolves, and validates the complete prototype set.

Current action contract

Each executable action definition contains:

• stable action_id;
• display name;
• default duration;
• optional preferred profession ID;
• target type: resource, activity, animal, or free movement;
• resource action ID when the action targets a ResourceNode;
• optional completion-cost resource ID and amount.

The current actions are gather food, gather wood, feed animal, deposit food, deposit wood, withdraw food, patrol, study, eat, rest, sleep, and wander. Idle and dead are stable state sentinels, not executable action definitions.

SimNPC reads default duration and preferred-profession metadata from these definitions. WorldViewManager reads target type and resource-action metadata instead of maintaining a separate gather-action map. ActionSelectionSystem and SimulationManager share the same completion-cost metadata, so patrol and study both require one stored wood without duplicating that rule.

feed_animal is the first animal-targeted action. Its definition prefers the farmer profession and declares an exact one-food completion cost. Selection, animal target reservation, and completion remain separate; NPC and player completion both use AnimalCareSystem's same pantry-to-animal transaction.

Current profession contract

Each profession definition contains a stable profession_id, display name, body color, and prop color. The current professions are farmer, woodcutter, guard, scholar, and wanderer.

NPC generation chooses from the registry's stable IDs. NPC state stores and restores those IDs as StringName, and rejects records that reference an unknown profession or executable action.

Opportunity vocabulary

SimulationIds defines the two proven opportunity types, restock_empty_pantry and supply_missing_wood, plus the stable open, resolved, and invalidated statuses. Invalidation reasons currently distinguish interested_died from evidence_stale. These are serialized vocabulary, not editor-authored quest definitions. Dynamic trigger, interested NPC, storage/resource goal, progress, exact resolution-event identity, and close reason belong to OpportunityStateRecord and VillageOpportunitySystem.

The shared record and lifecycle collaborator were extracted only after the food and wood consumers proved those fields. Their evidence, care, resolution, and invalidation rules remain explicit branches. Do not add a generic quest- definition registry until real acceptance, assignment, reward, or dialogue consumers establish a second shared contract.

Validation

The registry rejects:

• missing or duplicate IDs;
• empty display names;
• non-positive action durations;
• invalid target types;
• resource actions without a resource-action ID;
• incomplete, non-positive, or unknown completion-cost resources;
• references to unknown professions or resource actions;
• definition resources that fail to load.

tests/simulation_definitions_test.gd verifies registry integrity, definition-backed behavior, unknown-ID rejection, and serialization round-tripping.

Deliberate boundary

Definitions currently own identity and the static metadata already proven by the prototype, including the patrol/study completion-cost contract. They do not yet own:

• utility thresholds and consideration curves;
• general preconditions beyond stored-resource completion costs;
• completion effects;
• interruption and failure policy;
• reservation strategy;
• detailed target-selection policy beyond current resource/activity/free metadata;
• richer presentation hints beyond the current profession palette.

Selection, execution, target resolution, and visual travel are now separate responsibilities. The remaining concerns should move into definitions only when the action-system implementations prove a stable, reusable contract.