Survival Horror

What it is. A hostile dark you must cross with too little to cross it. Fuel, light, ammo, and health are scarce; the monster is a pressure, not a stat-check. You budget your way to dawn — every lit second spends a resource you can’t get back.

Player fantasy / why it’s fun. “I can survive this if I spend right — and I’m not sure I can afford it.” The fear is dread you can budget: horror that lives in arithmetic, so the player is always calculating, never merely reacting. Tension is a ledger with a monster leaning over it.

Pillars

Difficulty is resource arithmetic. The night is hard because the fuel economy is tight, not because the monster hits for more. Balance lives in a spreadsheet you expose to the player as scarcity.
Camping is impossible; the night is winnable — from the same numbers. One fuel inequality must prove both: you cannot hide until dawn, and dawn is reachable if you spend well. That single arithmetic sets the whole difficulty.
Wound before death; grace over instadeath. One grab is a story; two is a death. The genre’s mercy is a system-grace system — a wound state and buffered intent — not a coin-flip kill.

The loop stack

Layer	The beat
Moment	Spend light to see → move through danger → the meter drops.
Encounter	A room/threat: cross it on a fuel budget, take a wound or spend to avoid it.
Session	A night: reach dawn before the economy runs dry.
Meta	Nights, upgrades, map knowledge; scarcity eases as mastery grows.

Essential systems

System	Why this genre needs it
`system-economy`	Fuel/light/ammo faucets and sinks ARE the difficulty; a tight, honest ledger is the whole tension.
`system-grace`	The wound-before-death mercy; one grab buffers, two kills — grace as a system, unit-tested to the frame.
`pattern-pacing-and-tension`	Dread needs valleys (safe rooms, saved light) to make the peaks (a chase, a dark corridor) land.
`system-resource-loops`	Gather light/fuel → spend to survive → find more; the bottleneck is the pacing.
`system-save-and-checkpoint`	Horror respects the player’s time between dread spikes; a punishing retry loop turns fear into resentment.
`system-enemy-ai`	The monster must be readable and beatable — a pressure with tells, not an invisible dice roll.

Content & difficulty model

Prove both halves of the fuel inequality. From one arithmetic: a keeper/camping bot must die (you can’t hide to dawn) AND a diligent bot survives to dawn (the night is winnable). If camping survives, there’s no threat; if nothing survives, it’s unfair.
Light must collide with the world. Anything that interacts with light must collide with the light’s occluders — or shadows hide invisible, unfair killers. Prove light-repels and darkness-kills each as a rule, against the actual geometry.
Difficulty = tighter budget, not bigger numbers. A harder night gives less fuel, a longer dark, fewer safe rooms — never a monster with more HP. Scarcity scales; the monster stays a pressure.
Wound honesty. A grab wounds visibly and buffers; the next is lethal. Assert the grace window frame-exactly (same shape as any grace system).
Content is nights + map. New nights add a new arithmetic wrinkle (a new sink, a darker map); knowledge of the map is the real progression.

Signature-mechanic seeds

Survival horror but cozy by day, dread by night — you tend and rebuild in light, then defend on a fuel budget in the dark (tonal + structure; splices genre-farming-sim‘s calm against the night’s ledger).
Survival horror but knowledge is the only weapon — no combat; you survive by what you’ve learned about the monster’s rules (mechanic-swap toward anchor-outer-wilds; dread becomes deduction).
Survival horror but the light is a shared resource in coop — two players, one fuel ledger, forced communication in the dark (perspective + constraint; pairs with system-coop-and-competition).
Survival horror but every death rewrites the house — the map remembers and mutates around your failures (structure; systemic memory à la system-emergent-systems).
Survival horror but one candle, one screen, sixty seconds — a hard constraint that makes every second of light a decision (constraint).

Common pitfalls

Difficulty in monster stats. Scaling HP/damage makes horror a stat-check, not a budget; the fear evaporates into a health bar. Scale scarcity instead.
Light without occlusion. Shadows that don’t collide become invisible killers — the single most unfair bug the genre invites.
Campable nights. If hiding survives to dawn, there’s no threat; the fuel inequality exists to forbid it.
Instadeath. A coin-flip kill reads as unfair and breaks the budgeting fantasy; wound first, buffer intent, then kill.
Relentless dread. Unbroken tension goes numb; without safe valleys the peaks stop spiking. pattern-pacing-and-tension is load-bearing here.

Anchors

anchor-outer-wilds — knowledge as the only progression; the reference for the no-combat, dread-as-deduction bend, and for a curiosity-gated dark to explore.

Verify

Keeper bot survives to dawn; light-repels and darkness-kills each proven; fuel solvency inequality; golden night → design/FUN.md §16 · Survival horror. Author the ledger and the mood-predicate here; prove the inequality there.

Composes with

system-economy — the fuel/light ledger that IS the difficulty.
system-grace — the wound-before-death mercy that keeps dread fair.
pattern-pacing-and-tension — the valleys that make the dread spikes land.