rimlike/docs/design.md

rimlike — game design

Companion to memory.md. Read memory.md first for project north-star (pillars, vertical slice, open questions). This file is the game design: core loop, mechanics, simplifications from Rimworld.

Problem / motivation

A 2D, tile-based medieval-fantasy colony management sim — Rimworld DNA, Going Medieval as the closest lodestar — but slimmer and shaped for mobile / handheld. Most of Rimworld's fundamentals are present (pawns with needs and work priorities, base building, food production, hostile events, progression), but simulation, UI, and session length are tuned for short bursts on a small touch screen.

The aesthetic anchor is cute farming RPG meets medieval colony sim (peasants, wood/stone/iron, swords/bows, wild beasts) — bright, cheerful, Stardew-adjacent in palette while keeping the colony-sim depth of Rimworld and the medieval scope of Going Medieval. Driven by owned art (see art.md: ElvGames "Ultimate Farming RPG" bundle as primary, Ventilatore Fantasy Tileset as medieval accent secondary).

Core loop (one play session)

1. Open app → instant resume from autosave, brief "while you were away" summary (if any background events fired during the timeskip).
2. Triage → storyteller prompt(s) waiting (e.g. "Stranger arrived. Recruit?", "Winter in 4 days").
3. Plan → adjust work priorities, queue construction/research, designate areas. The slow, deliberate phase — pause is fine here.
4. Run time → game speed defaults to fast; auto-pauses on threats / pawn-down / dialog events. Player watches a few in-game hours fly by.
5. React → 1–2 events resolve.
6. Stop → close app at any time, autosave is always current.

Simplifications from Rimworld

What we deliberately do not build:

• No body-part injury system. Single HP per pawn + status effects (Bleeding, Infected, Sick, Tired, Hungry, Downed). ~80% of the drama for ~5% of the code.
• No deep social web. Relationships exist as +/- mood thoughts; no schism / lover triangles in MVP.
• No temperature simulation in MVP. Winter = food penalty + storyteller pressure, not a heat-leak simulation.
• ~4–5 skill categories (Manual Labor, Crafting, Cooking, Medicine, Combat) instead of 12.
• No mods/scripting in MVP — punt.
• No multi-Z-level / mountain-base. Single ground layer; "roofed" is a flag, not a Z.
• No prefab-house hand-painting. Players build tile-by-tile from walls/floors.

Skills

5 categories per pawn, 0–10 each. Level by use. Multiplicative speed/quality bonus on relevant work. Skills modify duration and quality, never permission — Bob with Cooking 0 can still cook, slowly and slightly worse.

Skill	Affects
Manual Labor	Mining, hauling, construction, chopping
Crafting	Workbench output, repair quality
Cooking	Meal speed and food poisoning rate
Medicine	Treatment success, infection clear rate
Combat	Hit chance, damage

Health & status effects

Single HP per pawn (default 100). Statuses tracked separately, each with severity 0–100, decay/grow rates, and an interrupt urgency flag (see architecture.md for how statuses become AI interrupts).

Status	Source	Effect
Hungry	Time without food	Slow movement/work; eventually damages HP
Tired	Time awake	Slow work; eventually forces sleep
Bleeding	Combat / accident	Continuous HP loss; high-priority interrupt
Sick	Storyteller / hygiene	Reduces work speed; needs rest + treatment
Infected	Untreated wound	Can escalate; treat with Medicine
Downed	HP near 0	Cannot act; carry to bed; bleeds out if untreated

Mood system

Per-pawn mood is a single 0–100 score, computed each tick as BASE + sum(thought_modifiers). Thoughts come from current state (persistent) or recent events (decay over time).

Mood bands & break risk

Band	Range	Effect
Inspired	90+	+20% work speed (rare positive event windows)
Happy	65–90	+10% work speed
Content	35–65	normal
Stressed	15–35	−30% work speed
Breaking	< 25 sustained ≥ 30 in-game min	soft break — see below

Soft breaks

When a pawn's mood is < 25 for 30 in-game minutes (sustained — momentary dips don't trigger), they enter a soft break, randomly sulking or wandering:

• Sulking — pawn walks to a quiet corner, sits there, won't accept work. Ends at mood ≥ 35 or after 8 in-game hours.
• Wandering — pawn paces aimlessly, refuses work, may eat/sleep. Ends same conditions.

Soft breaks are a player signal: "address this pawn's needs." No destruction, no violence in MVP.

Thought list (~13)

State-driven (persistent while condition holds):

Thought	Effect	Source
Hungry	−5 → −15 (severity ramp)	Hunger need ≥ 60
Tired	−3 → −10	Sleep need ≥ 70
Damp / Soaked	−3 / −6	Wet status (see weather)
Cold	−10	Outdoors during a Cold Snap
In darkness	−3	At night, in unlit tile (see Lighting)
Cramped quarters	−3	Sleeping in a room < 4 tiles (see Rooms)
Beautiful room	+3	Sleeping in a room with high beauty score
Ugly room	−3	Sleeping in a low-beauty / dirty room

Event-driven (fire and decay):

Thought	Effect	Decay
Slept well / poorly	+5 / +0 / −2 / −5 / −8 (sleep gradient, locked)	next sleep
Saw corpse	−3 (stacks per corpse)	8h
Ate raw food	−5	6h
Ate fine meal	+3	6h
Witnessed death	−10	2 days
Recently injured	−3 (while wound healing)	wound heal

Numbers are placeholders — tune in prototype.

The system is data-driven: thoughts live in a registry, easy to add/remove. We ship with these 13; expand by playtest.

Lighting

Each tile tracks "is this lit at night?" Lights are emitting furniture (torch, hearth, candle, oil lamp). Visual: lit tiles render in normal color at night; unlit tiles render with a darkening overlay. Players physically see darkness — atmosphere ahead of pure simulation.

Light sources (initial):

Source	Radius	Fuel	Build cost
Torch (wall-mounted)	3 tiles	none	2 wood
Candle	2 tiles	none	1 cloth
Hearth	5 tiles + warmth flavor	wood (slow burn)	10 stone, 5 wood
Oil lamp	6 tiles	oil (post-MVP fuel sim)	5 metal, 1 cloth

Fuel system simplified for MVP — most lights don't deplete; hearth consumes wood from adjacent stockpiles slowly. Full fuel-sim is post-MVP.

Rooms

Auto-detected from walls. Each enclosed area is a Room with:

• cells: Array[Vector2i]
• furniture: Array[Furniture] (everything inside)
• beauty: float (computed; see Beauty)
• dirtiness: float (computed; see Cleaning)
• inferred_type: String ("Bedroom" if contains bed; "Kitchen" if contains stove; else "Room")
• owners: Array[Pawn] (pawns whose beds are here)

Used by mood thoughts (Cramped quarters, Beautiful/Ugly room) and the day-summary screen ("Bob slept in his bedroom (beautiful)").

Rooms recompute when walls or furniture change; cheap given enclosure detection already runs.

Beauty & Quality

Beauty

Each furniture/floor/decor item has a beauty: int. Room aggregates as average beauty across cells; some items have wide influence (a statue contributes to a 5-tile radius even if it's one tile).

Categories displayed to player:

Beauty < −2     Ugly           "−3 mood Ugly room"
−2 ≤ B < 0      Dingy          slight negative
0 ≤ B < 3       Plain          no thought
3 ≤ B < 6       Nice           "+1 mood Nice room"
6+              Beautiful      "+3 mood Beautiful room"

Quality

All crafted items roll a Quality on creation: Shoddy / Normal / Excellent / Masterwork / Legendary.

• Roll function of crafter's relevant skill + RNG. Shoddy at low skill is common; Masterwork at high skill is rare.
• Quality multiplies item stats (weapon damage, armor coverage, bed comfort, beauty contribution to room).
• Item names are color-coded: grey/white/green/blue/purple.
• Affects all crafted goods: weapons, armor, furniture, meals.

The "Bob crafted a Masterwork chair" / "Mira's Legendary sword" moments are core Rimworld magic; this system lights them up.

Dirtiness & Cleaning

Floor tiles accumulate dirtiness: float (0..100):

• Dirtiness grows over time, faster on high-traffic tiles (pawns walking through), faster outdoors-tracked-in.
• Specific events spike dirtiness: blood from combat (~20), corpse decay (~5/h), spilled food.
• Dirtiness above 30 reduces room beauty; above 60 contributes "Ugly room" thought directly.

Cleaning is an 8th work category in the priority matrix. Cleaning Job toils: walk to dirty tile, perform timed cleaning (modified by Manual Labor skill), reduce dirtiness to 0.

Mostly low-skill chore work — gives Manual-Labor pawns something to do when not building/mining/hauling.

Production chains & workbenches

2-step chains where it makes medieval sense; 1-step where simpler is fine. Going Medieval / Banished flow without runaway recipe authoring.

Material flow

Raw material         Intermediate       Finished
────────────────────────────────────────────────
Wood log             —                  Walls/floors (1-step), furniture
Stone                —                  Walls (1-step)
Iron ore             Iron ingot         Iron tools/weapons/armor
Copper ore           Copper ingot       (decor/wires future)
Silver / Gold ore    Silver/Gold ingot  (currency / luxury items future)
Cloth / hide         —                  Beds, curtains (1-step furniture)
Grain                Flour              Bread
Vegetables           —                  Meals (cooked)
Meat                 —                  Meals (cooked)
Corpse               Meat (butchering)  →

Workbenches (5 in MVP)

Workbench	Skill	Recipes
Carpenter's bench	Crafting	Chair, table, bed, crate, barrel — wood goods
Smelter	Crafting	Iron / Copper / Silver / Gold ore → ingots (consumes wood as fuel)
Smithy / Anvil	Crafting	Iron tools (axe, pickaxe, hammer), iron weapons (sword), iron armor (helm/cuirass/boots)
Cooking hearth	Cooking	Basic meal, fine meal, bread, butcher (corpse → meat)
Millstone	Crafting	Grain → flour

Skipped for MVP: stonecutter (raw stone builds walls fine), tailor (no cloth clothing — only metal armor), drug lab, brewery.

Recipe authoring (~22 for MVP)

Each Recipe is a data record:

Recipe:
  id: "forge_iron_sword"
  workbench: "smithy"
  inputs: [{iron_ingot: 4}, {wood: 1}]
  outputs: [{iron_sword: 1}]   # quality rolled on creation
  skill: CRAFTING
  duration_ticks: 200
  min_skill_required: 0  // optional, default 0

Output quality is rolled at job completion based on crafter skill + RNG only. Input quality doesn't influence output (standard Rimworld/Going Medieval — keeps balance simpler).

Bills (recipe queue per workbench)

Each workbench has a list of Bills (queued recipes). A pawn with Crafting (or Cooking) work picks a bench with active bills and runs the next.

Bill modes (full Rimworld fidelity):

• Do X count — run this recipe N times, then remove the bill.
• Forever — keep running until paused or removed.
• Until N in stockpile — most-used; bill is dormant when stockpile + crate count of output ≥ N, becomes active when below.

Optional filters per bill:

• Ingredient quality minimum — "use Excellent+ iron ingots only." Bill waits if none qualify.
• Pawn skill minimum — "only Crafting ≥ 8 takes this bill." For Masterwork-attempting bills.

Bill priority within a workbench

Bills run in display order (top to bottom). Drag to reorder. The active pawn finishes the current job, then re-checks priorities.

Updated skill list (5)

Same five skills; Crafting now spans more bench types:

Skill	Affects
Manual Labor	Mining, hauling, construction, chopping, cleaning
Crafting	Carpenter, smelter, smithy, millstone — quality of crafted goods
Cooking	Cooking hearth, butchering, food poisoning rate
Medicine	Treatment success, infection clear rate
Combat	Hit chance, damage

Updated work category list (9)

Construction · Mining · Hauling · Cleaning · Crafting · Cooking · Plant · Doctor · Combat

The priority matrix is now 9 columns wide. Still scrollable on a phone (sticky pawn-name column, swipe horizontally).

Storyteller

Sandbox + light storyteller prompts — soft, dismissible nudges that give each short session shape without forcing scenarios. Per Tynan Sylvester's design talks: drama from situation, mix of opportunity and threat, quiet/threat alternation, player choice for big events.

Picker mechanism

• Daily roll at 6am in-game time. Storyteller picks one event from a weighted pool.
• Cooldowns per category: no two threats within 3 days; no two wanderers within 5 days; nudges fire at most once per pawn-need-state.
• Tension model: a running "tension score" tracks recent dramatic events. High tension → reduce threat weight. Low tension → boost threat weight. Keeps the pacing breathing.
• State-triggered events (e.g. "First Beds" fires while no beds exist) get higher weight than random ones.
• Display flavor:
  • Nudges → ambient top banner, no pause, dismissible.
  • Seasonal/ambient beats → ambient banner with seasonal art tint.
  • Modal events (wanderer, threat, disease, choice) → auto-pause + dialog.

Prompt corpus (MVP — 25 prompts)

🌾 Soft nudges (dismiss-only, low priority)

ID	Title	Body	Trigger	Effect
1	First Beds	"Your settlers slept on the cold ground again. They are starting to ache."	day 2+, beds < pawn count	nudge only
2	Empty Larder	"The larder is bare. Spring won't last forever."	day 3+, no farm zone	nudge
3	No Fire	"Without a hearth, the cold will bite by night."	day 4+, no hearth/torch	nudge
4	Walls?	"Sleeping under stars is romantic until the wolves arrive."	day 5+, no walls	nudge

🍂 Seasonal beats (ambient banner)

ID	Title	Body	Trigger	Effect
5	Spring Awakens	"The thaw runs in every stream. Crops will grow fast now."	spring start	+10% crop growth season
6	Summer's Heat	"The sun beats down. Unsheltered work will tire faster."	summer start	outdoor work −5%
7	Autumn's Harvest	"The fields are heavy with the last of the year's bounty."	autumn start	+15% harvest yield
8	Winter's Edge	"Frost has come. The road is closed; you are alone."	winter start	no wanderers for 5 days; threat weight ↑

🚶 Wanderer events (modal, choice)

ID	Title	Body	Trigger	Choices
9	A Traveler	"A weary traveler stumbles toward your gate. They look hungry. Will you welcome them?"	ghost state OR ~8 days	Welcome (+1 pawn) / Send away
10	The Refugee Family	"A family fleeing bandits arrives. They have nothing, but they would work hard."	post-day-15	Welcome (+2 pawns, low skills) / Refuse (−2 mood colony 1 day)
11	The Old Soldier	"A retired soldier offers his blade for a place by your fire. Combat 8, but old and tired."	post-day-20	Welcome / Refuse
12	The Wandering Healer	"A traveling healer asks for shelter. She brings knowledge of medicine."	any pawn Sick	Welcome (+1, Medicine 6) / Refuse

🐺 Threat events (modal, auto-pause)

ID	Title	Body	Trigger	Effect
13	Wolves at the Edge	"Wolves howl in the distance. They will be here by nightfall."	season-weighted threat slot	1–3 wolves at edge in 2h
14	Lone Wolf	"A starving wolf circles your livestock."	low-threat random	1 wolf
15	Pack Hunt	"A hunting pack moves through the forest. They smell your colony."	post-day-30 threat	4–6 wolves
16	Bandit Scouts	"Strange figures watched from the treeline at dusk. Bandits, perhaps."	post-day-25	flavor; raises threat-likelihood (foreshadow for v2 raids)

🤒 Disease & misfortune (modal or nudge)

ID	Title	Body	Trigger	Effect
17	Fever	"%pawn% woke with a fever. The sickness may spread."	random ~30 days	Sick on random pawn; 20% daily spread to neighbors
18	A Bad Cut	"%pawn% gashed their hand chopping wood. The wound looks deep."	chop job, low chance	Bleeding on pawn
19	The Sleeplessness	"%pawn% has barely slept. Something weighs on them."	random, low-mood pawn	Tired worsens; mood penalty 2 days

🌾 Resource & opportunity

ID	Title	Body	Trigger	Effect
20	Bountiful Harvest	"Your fields exceeded the season. The granary swells."	harvest, random	+25% yield this harvest
21	Lumberjack's Luck	"%pawn% found a copse of unusually thick trees."	chop job, random	next 3 trees +50% wood
22	Veins of Iron	"A miner reports a rich vein, deeper than expected."	mine job, random	next mining yield ×2

🏰 Discovery / lore (flavor, dismiss)

ID	Title	Body	Trigger	Effect
23	Strange Stones	"Settlers report finding carved stones in the wood — older than any memory."	random, post-day-15	flavor only
24	An Old Map	"%pawn% found a tattered map. Roads to the north, half-faded."	random, post-recruit	flavor (seeds v2 trade/exploration)

🌟 Milestone (rare, celebratory)

ID	Title	Body	Trigger	Effect
25	One Year Survived	"A full year. The first frost feels different now — yours is a real settlement."	end of first winter	+5 mood "We made it" colony 2 days

Authoring guidelines

• Voice: medieval, a touch of melancholy/grit. Avoid modern phrasing.
• Length: 1–2 sentences. Anything longer feels like a wall on a phone.
• Use %pawn% substitution for personalized events. Game replaces with the relevant pawn's name.
• All copy is in a string table — i18n-ready from day one.
• New prompts = new rows in a JSON registry. Trivial to expand post-MVP.

Combat

Realtime with auto-pause on threat. Two-roll resolution (hit, then damage). Cover from walls + trees. Downed-then-rescue death model for sim drama.

Weapons (3 in MVP)

Weapon	Type	Damage	Range	Speed	Recipe
Sword	Melee	8	1 (adjacent)	1.0 atk/sec	4 iron ingot + 1 wood
Axe	Melee	12	1	0.7 atk/sec	3 iron ingot + 1 wood
Bow	Ranged	10	8 tiles	0.5 atk/sec	1 wood + 1 cloth

Quality multiplies all stats (Masterwork sword = 12 dmg @ 1.5 atk/sec).

Unarmed pawns fight with fists: 3 damage, 0.5/sec. Used when cornered without a weapon.

Armor (3 slots)

Slot	Iron variant armor value	Recipe
Helmet	3	3 iron ingot
Cuirass	8	5 iron ingot
Boots	2	3 iron ingot

Total iron set = 13. Quality multiplies. Each slot independent — pawn can wear partial armor. Leather/cloth variants post-MVP (lower armor, lower mood penalty for hot weather).

Cover (walls + trees)

A target is "in cover" if a wall or tree tile sits between the target and the attacker along line-of-sight.

• Wall — full cover, −40% to hit
• Tree — partial cover, −20% to hit

Cover is checked per-attack. Multiple cover sources don't stack (highest applies).

Hit / damage resolution (two roll)

# Roll 1: hit
hit_chance = 50% + (combat_skill × 5%) − cover_penalty − (range_penalty if ranged)
range_penalty = max(0, (distance − 2) × 5%)
hit = (random() < hit_chance)

# Roll 2: damage (only if hit)
damage = weapon_damage × quality_multiplier − target_total_armor
damage = max(1, damage)   # always at least 1 damage on a hit
target_hp -= damage

Skill 10 pawn at adjacent range with no cover: 50% + 50% = ~100% hit before clamps. Same pawn at range 8 with bow against treed target: 50% + 50% − 20% (cover) − 30% (range) = 50%. Tunable.

All numbers placeholders — tune in prototype.

Downed & death

When HP reaches 0, pawn enters Downed status (not dead). Behavior:

• Drops their weapon to the ground.
• Cannot move or take any job (Layer 1 of decision pipeline).
• Bleeding continues if untreated → HP stays at 0 → death after 6 in-game hours untreated.

Rescue flow:

• Doctors auto-prioritize Downed colonists (Doctor work).
• Job: walk to Downed pawn → carry → walk to nearest bed → place in bed.
• Pawn in bed gets Resting status; doctor visits to treat (clears bleeding, infection); HP regenerates over ~2 in-game days.

If no doctor reaches the Downed pawn in time → death → corpse entity → handled by stockpile system (Corpses filter category).

Combat priority semantics — "Off = defends if cornered"

A pawn with Combat priority Off:

• Won't accept the player's forced "Attack target" job.
• Won't autonomously move toward threats.
• Will fight back if an enemy is adjacent and no escape path is reachable (5-tile pathfinder check).
• Tries to flee toward map interior / nearest indoor zone when threats appear.

A pawn with Combat priority High or Critical: actively engages threats in range, holds position, takes player commands.

Forced commands

Player taps a pawn → bottom sheet → Attack target → tap an enemy. Issues a forced job (Layer 5 of pawn AI). Pawn engages with priority.

Same flow for Carry to bed (manually rescuing a downed pawn) and Patrol (post-MVP).

Auto-equip

Pawns with Combat > Off auto-equip the best available weapon they can carry, prioritizing higher quality. Player can override via long-press on a weapon item → Assign to Bob. Locks the assignment until cleared.

Friendly fire — ON

Projectiles travel along their LOS path; any pawn in the path is a potential hit (with reduced chance vs the intended target). Standard Rimworld semantic. Adds tension to ranged formations.

Wolf AI (MVP's one threat type)

• Storyteller fires wolf events at night, weighted by season (more in winter).
• Wolves spawn at map edge in a small pack (1–4).
• Approach the colony, engage pawns or animals.
• Have natural weapons (bite: 6 damage, 1.0 atk/sec) and minor armor (tough hide: 2 armor).
• Flee at HP < 30% — pacing keeps them from being trivial swarm fodder.
• Death = corpse, butcherable for ~5 meat at the cooking hearth.

Stockpiles & hauling

The unsung 30% of pawn-time. Storage has two coexisting forms: floor stockpile zones (areas painted on the world) and containers (furniture you build). Both share the same filter + priority model; haulers treat them as a unified pool of destinations.

Filter categories — 16 chips

Materials	Food	Equipment	Misc
🪵 Wood	🥕 Vegetables	💊 Medicine	⚰ Corpses
🪨 Stone	🍖 Meat	⚒ Tools
⚙ Iron ore	🌾 Grain	⚔ Weapons
🟤 Copper ore	🍞 Cooked meals	🛡 Armor
⚪ Silver ore
🟡 Gold ore
🧵 Cloth & hides

Tap-toggle in a 4×4 chip grid per stockpile or container. (Future expansion: split Wood by species, etc. — punted.)

Priorities — 5, Rimworld semantics

Critical / Important / Preferred / Normal / Low. Items flow from low priority to high automatically:

• Critical — pulls items from anywhere, immediately. The "I want this filled NOW" zone.
• Important — pulls from Preferred and below.
• Preferred — default for "nice" stockpiles (e.g. kitchen-adjacent food).
• Normal — standard.
• Low — dump zone. Items here move OUT to higher zones when those have space.

Pawns periodically rescan (every ~5 sim seconds) to migrate items low→high without burning CPU.

Containers

A Crate is a furniture entity, built like any other (Build → Furniture → Crate). MVP ships one generic crate type: 4 stacks capacity, any allowed item types (configurable post-build). Different sizes / specialized crates are post-MVP.

• Independent of zones — placed anywhere, has its own filter + priority.
• Same 16-chip filter and 5-level priority as floor zones.
• Tap a crate → inspect screen (filter, priority, contents, Empty / Move / Demolish).
• Pawns walk adjacent (4-neighbor) to drop into a crate; container tile itself is impassable.
• Capacity: 4 stacks of allowed types.

Crates exist alongside floor stockpiles. Use floor zones for high-volume bulk (logs in a lumber yard); use crates for organized indoor storage (kitchen pantry, armory).

Stacks — one per tile, one item type per tile

Mixed tiles disallowed. Visual quantity badge per tile. Stack maxes:

Item	Max stack
Wood, stone, cloth, ores	50
Vegetables, meat, grain	25
Cooked meals, medicine	10
Tools, weapons, armor, corpses	1

Pawn carry

One stack at a time, capped at pawn's carry capacity (~25 wood per trip on the average pawn). Multi-type carry is v2.

Workbench output drop tile

Each workbench has one designated cell in front. Products land there; haulers clear it via the normal pipeline. Avoids the Rimworld kitchen-mess problem.

Forbid / allow

Long-press item → toggle hauling. Forbidden items get a 🚫 badge; haulers ignore them.

For data structure + hauling AI, see architecture.md. For zone painting and crate inspect UI, see ui.md.

Roofing, indoor, weather

Temperature simulation is cut (locked). What remains is the indoor/outdoor divide that powers shelter motivation.

Indoor = roofed

A tile is indoors if it has the Roof flag set on Layer 4 (see architecture.md). No further enclosure check at sim-time — we trust the auto-roof system to only place roofs in sensible places.

Auto-roof, not player-placed

When walls form an enclosed area ≤ 8 cells across, the interior auto-roofs. No "place roof tile" verb. BFS from interior cells when walls change; if every direction hits a wall within 8 cells, mark Roof. Cap prevents a fence around a meadow from roofing a stadium.

Matches the player's mental model: "I built four walls, now there's a room."

Big-room UX (open): the ≤8-cell cap silently fails on rooms larger than 8×8. When the player encloses a too-large area, we should surface "this area is too large to roof — split it with an interior wall." Exact threshold + UI treatment is TBD (see memory.md Open questions).

"No-roof" designation

Designation type: paint cells inside an enclosure to forbid auto-roofing. Useful for courtyards, fire pits, gardens. Same paint UX as stockpile zones.

Roof rendering — none in MVP

Roofs are sim data only. Indoor tiles get a subtle tint (faint blue-grey overlay). No X-ray toggle. This is the genre convention for top-down sims (Rimworld does the same). Visible roofs = v2 polish.

What roofing protects against

Effect	Outdoor	Indoor (roofed)
Mood penalty for being in rain	−3 (Wet)	none
Mood for sleeping	−5/−2	+0/+5
Snow accumulates	yes	no
Food spoilage in heat wave	faster	slower
Plants grow	yes	no

Crucially: plants don't grow indoors. No skylights / hydroponics in medieval scope. Gardens must be outside, so weather matters even after walls go up.

Weather — 4 types, daily roll

Simple state machine. At sunrise, storyteller picks the day's weather, weighted by season.

Weather	Effect
Clear	nothing special
Rain	outdoor pawns/items accumulate Wet; food spoilage slows
Storm	heavier rain, faster Wet, mood penalty outside, no harvesting jobs assigned
Cold snap	outdoor pawns: −10 mood, hunger grows faster

Seasons

4 seasons × 12 in-game days = 48-day year (~4 real-time hours per year at default speed).

Season	Clear	Rain	Storm	Cold snap
Spring	50%	35%	10%	5%
Summer	70%	20%	10%	0%
Autumn	50%	30%	15%	5%
Winter	30%	25% (as snow)	25%	20%

Weights are placeholders — tune in prototype. The shape (winter rough, summer kind) is locked; numbers are first guesses.

Storyteller can override for narrative beats ("a hard winter approaches").

Wet status

Pawns in rain accumulate Wet (0–100). Decays indoors, grows outside.

Wet 0–25:  no effect
Wet 25–60: −3 mood "Damp"
Wet 60+:   −6 mood "Soaked", small movement-speed penalty

Decay ~5/in-game-hour indoors; accumulation ~10/h in rain, ~20/h in storm.

Numbers are placeholders — tune in prototype. Thresholds, decay rates, and accumulation rates are starting values, not locked decisions.

Sleep mood (the strong gradient)

+5  Slept in bed, indoors
+0  Slept in bed, outdoors (under stars)
−2  Slept on bedroll/ground, outdoors with no bed
−5  Slept on the ground, indoors
−8  Slept on the ground, outdoors

Forces players to build (a) beds and (b) walls/roof to house them. Simple, legible gradient.

Numbers are placeholders — tune in prototype. The shape (worse outdoors, worse on ground, both compound) is the design intent; specific values get tuned by playtest.

Explicitly not simulated

• Temperature (locked).
• Wall-material insulation — all walls equivalent.
• Lightning, fires — defer.
• Wind, projectile drift — defer.
• Sunlight angles — plants either get sky (grow) or don't.

Failure state — Ghost colony

When all colonists die or leave, the world enters ghost state. No game-over screen.

• Buildings, stockpiles, containers, items, beds — all persist exactly as they were.
• Time continues at slow speed; pawn-side simulation is paused.
• Within 3–5 in-game days, the storyteller fires a Wanderer event: a stranger arrives at the map edge, prompting recruit/refuse.
• If accepted: new pawn enters, you control them, ghost state ends.
• If refused: another wanderer eventually appears; world stays ghost until accepted.

Why this works for mobile: "lost my colony of 200 hours" on a phone is brutal UX. Ghost state preserves the world, the player's investment, and lets a session end on a softer note. Permadeath drama still lives in individual pawn deaths.

Death & corpses

Cause of death tracking

Each pawn entity stores death_cause: String and death_day: int. Used by pawn-detail screen ("Bob the Carpenter — died Day 27 of Spring 1, killed by wolf") and by grave markers (tap a grave → see that screen).

Corpse decay

Corpses decay over time. Each corpse has decay_severity: float (0..100), growing ~33/in-game-day:

Severity	State	Effect
0–50	Fresh	Butcherable for ~5 meat. Standard −3 mood per stack.
50–100	Rotting	No longer butcherable. Mood penalty grows: −5 per stack. Visible green-grey tint.
100	Rotted	Still removable (bury or cremate); butcher disabled.

Rotting corpses don't attract predators in MVP (clean cut for scope) — but rot creates urgency: bury or cremate fast.

Burial mechanic

Designate a Graveyard zone — a special stockpile that only accepts Corpses (filter has a single chip on, Corpses).

Burial Job toils (Construction-priority pawns):

walk to corpse → carry → walk to graveyard cell
→ dig grave (~30 sim sec, modified by Manual Labor skill)
→ place corpse → place grave marker tile

Result: corpse entity destroyed, grave marker placed. Marker is a 1-tile decorative entity:

• Beauty: +1 (modest contribution to room beauty)
• Persistent until demolished
• Tap → opens pawn-detail showing the deceased's record

Cremation pyre

Buildable furniture (Build → Furniture → Pyre, costs ~10 stone + 5 wood). Plays the role of a workbench but accepts a single recipe:

• Cremate corpse — input: 1 corpse + 5 wood. Output: nothing (corpse gone). Time: ~20 sim sec. Skill: Crafting.

Player adds a "Cremate" bill to the pyre; a Crafting-priority pawn auto-hauls a corpse, walks to the pyre, performs the rite (visual: brief flame + smoke), corpse destroyed.

Faster than burial; doesn't preserve a memorial. Clean for "send the wolves we killed back into the world."

Grave markers

Single-tile decorative entity placed by burial. Beauty +1 each. Cluster in a graveyard zone gives a small "Beautiful (somber) garden" feel — beauty bonus stacks.

Tap a marker → pawn-detail screen for the deceased: name, role, death day, cause, days-lived, statuses-at-death.

What we deliberately don't build

• Resurrection — no MVP feature. Death is permanent.
• Hauntings / ghosts — flavor for v2, not needed.
• Funeral ritual with attendance + mood — interesting but adds a system.
• Decay attracts predators — was an option; cut for MVP scope (creates negative-feedback-spiral risk).

What lives elsewhere

• Pawn AI / job system, work priorities mechanics — see architecture.md.
• Touch UI for work priorities + other screens — see ui.md.
• Tileset strategy + assets + art license — see art.md.
• Vertical slice spec — see memory.md.