What is Beamzag?
A daily laser-and-mirrors puzzle. Place an exact number of mirrors so the beam lights every gem and lands in the socket. Every board is solver-checked to have exactly one answer, so you never have to guess. Boards grow from a 5x5 on Monday to an 8x8 on Saturday, and on Sunday two lasers share one tray of mirrors. Free, with no account.
How to play Beamzag
- A laser fires into the grid from one edge and a socket sits on another edge.
- Tap an empty cell to place a mirror as /. Tap again to flip it to . A third tap removes it.
- Mirrors turn the beam 90 degrees on either face. Gems light when the beam passes through them. Walls stop the beam. Mirrors cannot sit on gems or walls.
- The tray shows the exact number of mirrors available. The solution uses every one of them.
- You win when every gem is lit and the beam finishes in the socket.
- Undo reverses the last tap. Reset clears all your mirrors. Two hints are available; each places and locks one correct mirror.
- Sundays are Twin boards: two lasers and two sockets share one tray of mirrors. Either beam can light any gem, but each must reach its own socket. Beams may cross and a single mirror reflects both.
Board size and difficulty by day
Monday uses a 5×5 grid with 2 mirrors (gentle). Tuesday is 6×6 with 3 mirrors (easy). Wednesday and Thursday stay on medium difficulty with 4 mirrors on 6×6 then 7×7 grids. Friday rises to hard with 5 mirrors on 7×7. Saturday is expert: 8×8 with 6 mirrors. Sunday returns to hard as an 8×8 Twin board with 5 shared mirrors.
A generator creates each board and an exhaustive solver confirms that no fewer mirrors work and that only one arrangement of the given number succeeds. Boards are prepared more than a year ahead, so the daily puzzle loads locally without a server.
Tips for finding the single solution
Work from both ends. The laser fixes the starting path and the socket fixes the final direction, leaving only the middle open. Count the required turns: every mirror is one 90-degree change and all must be used, which eliminates many possible routes early. A mirror does nothing unless the beam reaches it, so cells no route can touch can be ignored. Walls often block the shortest path and force a longer route that needs the full set of mirrors.
The share card records one square per tap, coloured by how many gems were lit after that move. It shows the search path without revealing mirror positions. Stats and streaks stay in the browser. Practice mode offers three boards a day drawn from a pool of 300; wins there count as extra solves but do not extend the daily streak.