A solo deduction horror game

Ten walked in. The door sealed behind them.

Two signs in the house are cursed. Every night, the entity kills one detective. Study the deaths, read your rivals, and name the two cursed signs — or leave the house and live with the not-knowing.

Coming soon toGoogle Play Coming soon to theApp Store
or see how a night unfolds ↓
Chance is an illusion. With enough study, anything is solvable.

All ten detectives share that belief. The house will test it. There are no safe rooms, no jump scares, and no reflexes required — only evidence, patience, and the question of how long you dare to stay.

How a night unfolds

The game is a cycle of days and nights. Each night you survive is 1 point. Each death is a clue.

The morning meeting

The detectives still alive gather. Some say where they are going tonight, and mean it. Some stay silent. The AI rivals remember whether you went where you said you would — across games.

Pick a room

Choose where to sleep among twelve rooms of five signs each. Every room holds at least one cursed sign. Nowhere is safe.

Night falls

The entity kills exactly one detective. Their room's signs go public, and one is confirmed not cursed. The dead teach the living.

Deduce — or leave

Narrow ninety-one possible pairs of signs down to one. Then decide: another night of evidence, leave the house, or the Confrontation.

Every morning, the same choice

The safe way out

Leave the house

The door unlocks every morning. Leave with 1 point for every night you survived — and leave the mystery to the others.

1 point per night
The long game

Stay another night

More nights mean more deaths, more confirmed-safe reveals, and a shorter suspect list. They also mean another draw from the entity.

Evidence accumulates
The last deduction

Confront

Seal a vote naming the two cursed signs. Correct, and the case is solved for ten times your nights. Wrong, and you die.

nights × 10 — or death

Fourteen signs. Two are cursed.

Ninety-one possible pairs. A blind guess succeeds 1.1% of the time. A patient detective does better.

  • Mirror
  • Candle
  • Clock
  • Book
  • Bottle
  • Chest
  • Vase
  • Locket
  • Chandelier
  • Hourglass
  • Mask
  • Rose
  • Feather
  • Crown

The two cursed signs change with every visit. Watch closely.

Why The Last Deduction?

Pure deduction

Evidence over reflexes: deaths, reveals, and failed Confrontations are your only clues.
Fair by construction: every case is solvable, and the AI rivals see exactly what you see.

Nine rivals worth reading

Named personas: talkers, hoarders, and gamblers who play to win — with or without you.
Your word persists: rivals remember whether you went where you said you would, and it follows you into the next game.

The Bestiary

Thirteen entities: crowd hunters, lone stalkers, and worse — each changing who dies in the night.
Hidden until the end: the killer's identity is its own small deduction.

Beautifully scary

Dread, not shock: no jump scares, no strobing, no screen shake — the horror lives in slowness and absence.
Every effect has a dial: motion, light, atmosphere, sound, and haptics are all individually adjustable.

A career of cases

Quick Play is free: the full classic game, forever.
Premium: one purchase, paid once, opens Career and Tournament: a ladder of authored cases, ranks, tools, and tournaments.

Offline & private

Plays offline: no accounts, no cloud, no tracking. Only the store's billing uses the network: the purchase, a restore, Google Play's check that a purchase still stands, and Google's billing logs on Android.
Procedural art: every house is drawn by code and seeded by your game — no two cases look alike.

Is this for you?

You may be here because you said one of these:

  • “I want a social deduction game I can play alone.”
  • “I want a deduction game like Return of the Obra Dinn or The Case of the Golden Idol, on my phone.”
  • “I want a slow-burn mystery, not a jump-scare game.”

Like Return of the Obra Dinn, but you play it by sleeping in a haunted house with nine rivals. It plays offline, with no account and no ads.

It is not for you if you want multiplayer lobbies or a tabletop role-playing campaign.

Premium

Premium opens Career and Tournament.

“Premium” is one payment, and it unlocks:

  • Career, from the Prologue on
  • Ranks and a reputation that carry from case to case
  • A recurring cast, and authored cases

You pay once. There is no subscription. The store shows the price for your country, in your currency, before you buy.

Bought it before, or on another device? The app restores it from the same store account.