Black Box
Infer hidden objects from beams sent through a box.

Your session starts here.
English game interface · Landscape recommended on phones
Choose Load game to start.
- Input
- Pointer
- Language
- English
- Screen
- Landscape recommended on phones
- Progress
- Stored by the game host
Inside Black Box
Infer hidden objects from beams sent through a box. Compare beams from two directions before committing to a hidden position. Click the border to fire a beam; click inside to mark a suspected ball.
The game retains its English interface. Its own menus and tutorial describe the current release.
Make your move.
- Click the border to fire a beam; click inside to mark a suspected ball.
- Use the game’s own menu for a new round, difficulty and sound options where available.
Click or tap inside the player before using keyboard controls. Landscape recommended on phones. Touch support does not guarantee the same performance on every phone.
A good place to start.
Compare beams from two directions before committing to a hidden position.
Session notes.
Pause, reload & saved progress
Pause using the game’s own controls before leaving. SENOVIRA cannot reliably pause or mute an external game. Reload restarts the frame and may discard unsaved progress; Unload removes it. Neither clears the game’s storage. Browser privacy settings may separate embedded and direct saves.
Playing & savesCreator, license & official release
Simon Tatham and contributors · MIT
Black Box by Simon Tatham and contributors. MIT license. Official release embedded without modifying its code. Separate hosting policies apply.
Source code may be newer than the playable release. Loading the player contacts www.chiark.greenend.org.uk; this host controls the game’s requests and storage.