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MRIGuessr
Getting started

How to play

Read a slice of a brain scan and pinpoint the highlighted spot on a 3D brain. Three rounds, then a summary.

  1. Inspect the slice

    You start with a single MRI slice. Scroll to look around within it.

  2. Reveal if you need to

    Unlock neighbouring slices for more context — the first slice is free.

  3. Choose a path

    Click the 3D brain to send a line through it toward your suspected location.

  4. Set the depth

    Slide from the surface to the far side to place your guess inside the brain.

  5. Submit & compare

    Reveal the target, your distance, and what you got right.

The information trade-off

The first slice is free. Revealing more slices helps you localize, but lowers the maximum scoreyou can still earn. A confident, accurate guess with a bit more information can still beat a rushed, inaccurate one — it’s your call.