Definitions & Industry Terms

What is a whodunit?

By the WriteLoom editorial teamUpdated 2026-06-07
Key facts
  • A whodunit is a mystery centered on identifying the culprit.
  • The central question is "who did it?"
  • It relies on clues, suspects, and red herrings.
  • Fair play lets the reader theoretically solve it.
  • It is a classic subgenre of detective fiction.
Direct answer

A whodunit (from "who done it?") is a mystery in which the central question is the identity of the culprit — usually the perpetrator of a crime, often a murder. The story revolves around clues, a cast of suspects, red herrings, and an investigator working toward the reveal. The defining feature is fair play: the reader should, in principle, be able to solve it from the clues provided. A staple of classic detective fiction, the whodunit is built around the satisfying puzzle of "who did it, and how."

Chapter i·Why it matters

The whodunit is a foundational mystery form with specific conventions — fair-play clueing, suspects, a logical solution — that writers must understand to satisfy the genre's devoted readers. Knowing what defines a whodunit (the central identity question and the fair-play contract) helps writers construct mysteries that play fair and deliver the puzzle-solving satisfaction readers seek. It clarifies a core mystery structure, distinct from thrillers or other crime fiction where the culprit may be known.

Chapter ii·What to include

  • A mystery centered on the culprit's identity.
  • The "who did it?" question.
  • Clues, suspects, and red herrings.
  • Fair play for the reader.
  • A logical, satisfying solution.
  • Its place in detective fiction.

Chapter iii·Example

A writer plans a whodunit: a murder, a closed circle of suspects each with motive, a trail of clues and red herrings, and a detective who assembles them. She clues it fairly so an attentive reader could solve it. The central question — who did it? — and the fair-play puzzle define it as a whodunit.

In WriteLoom

WriteLoom's Plan studio tracks your clues, suspects, and solution, so a whodunit plays fair and satisfies.

See the Plan studio