Systems

designed · Phase 1 (#34, #36, #37) · PLAN §3.8, §15, §18.2

Nine systems run Riverside Village. Each is a plugin implementing ISimulationSystem: it reads the frozen view, yields intents, holds no state, and can be switched off at any tick boundary. New systems start inactive in the default loadout until their increment's done-when passes.

Phase	Pri	System	Reads	Writes	Issue
Environment	5	DayNightSystem	world_time, temperature	ambient_temperature, temperature (Outdoor)	#34
Environment	20	HeatSystem	temperature, ambient_temperature	temperature	#34
Environment	40	FireSystem	OnFire, Combustible, temperature, ignition_point, fuel, water_level	OnFire, temperature (via propagation), fuel; events ignition, fire_spread, extinguished	#34
Environment	100	GrowthSystem	food_value	food_value	#34
Agency	10	PerceptionSystem	containment, permeability.*, temperature, salient attributes	perceived_entities, perceived_danger, perceived_warmth; knows edges	#36
Agency	20	HungerSystem	hunger	hunger	#36
Agency	21–29	BaselineOptions (publisher)	perceived_*, hunger, energy, facts	options (bus)	#35
Agency	30	DecisionSystem	ctx.Options, personality_*	current_action, current_action_target, current_action_reason	#37
Agency	40	ActionSystem	current_action*	edges, hunger, food_value, water_level, fuel; events	#37
Event	—	LifecycleSystem	hunger, temperature	DestroyNode, dropped items; npc_death	#34
Agency	1	PlayerActionSystem (engine, not toggleable)	the queue	intents player:<id>	#39

Later phases add systems the same way — a plugin, a manifest, a row here — and the core does not change.

What every page here has

Purpose · phase and priority · the formula or algorithm · manifest (reads / writes / options / events / settings in sim-time) · hot-toggle behaviour · what the trace records · status and history. The design depth is PLAN §7.4.1 and §11.4–11.5; if a page and the plan disagree, the plan is fixed first.