About

Casebook is the single-player crime-scene deduction game

One player. One browser tab. You search the crime scene yourself, put the suspects’ statements side by side, find the one that cannot be true, and name the killer.

What Casebook is not

  • Not a casebook in the legal sense — it is not a law-school textbook or a collection of court opinions.
  • Not case-management or social-work software. An unrelated product shares the name; this is a mystery game.
  • Not a multiplayer party game. There is no host, no group, and no scheduling — every case is built for exactly one player.

How a case works

  1. Read the opening: the setting, the victim, and the question the case asks.
  2. Search the scene. Clues are not highlighted for you — you have to look.
  3. Compare testimony across suspects and find the statement that cannot be true.
  4. Rule out possibilities in a notebook, then accuse exactly one person.
  5. After the verdict, read the full account and check what each clue actually pointed to.

Fairness is a build step, not a promise

Every case is run through a deduction engine before release. It has to prove that exactly one solution is reachable from the clues a player can actually find. A case that can be solved two ways, or that needs a clue the player can never reach, does not ship. Difficulty comes from hiding the contradiction well — never from withholding the evidence you need.

Catalogue and pricing

Season 1 is 20 cases (a 20-case season). The first case is free with no account. Individual cases are priced at 2,900 KRW as a one-time purchase — there is no subscription. Payments are not open yet.