How to play Beamzag

You get a small grid, a laser, a socket and an exact number of mirrors. Put the mirrors down so the beam lights every gem on its way into the socket. There is a new board every day, and each one has exactly one answer.

The rules

The laser fires into the grid from one edge. The socket sits on an edge as well.
Tap an empty cell to put a mirror there. It goes down as /. Tap it again to flip it to \, and a third time to pick it back up.
A mirror turns the beam 90°. Both faces reflect, so it does not matter which side the beam hits.
Gems light up when the beam passes through them, and the beam carries on. Walls stop it. Mirrors only go on empty cells, never on a gem or a wall.
The tray under the board shows how many mirrors you have, and the answer uses every one of them.
You win when every gem is lit and the beam ends in the socket. Each board has one answer, so if yours does that, it is the answer.

What is on the board

Laser, on the edge where the beam comes in
Socket, where the beam has to finish
Gem, still dark
Gem, lit by the beam
Mirror, one tap for / and two for \
Wall, which stops the beam

A worked example

This is a 4×4 board with three mirrors. Rows count from the top and columns from the left. The laser comes in on the left edge of row 2, the socket is on the bottom edge under column 1, and there are two gems and one wall.

With no mirrors down, the beam runs straight along row 2 and out the right side. It already lights the first gem on the way.

Start at the socket. It is under column 1, so the beam has to finish by heading straight down that column. One mirror has to sit in column 1 to turn it, but not on row 2. That is where the beam comes in, and a mirror there would turn it before it reaches the first gem.
Now the second gem, on row 3 in column 3. The shortest way to it is to turn down right after the first gem: a \ on row 2, column 3 sends the beam down through it. But you cannot put a mirror on a gem, so nothing turns the beam there, and it runs into the wall on row 4.

The short route. The beam lights the second gem and then stops at the wall, nowhere near the socket.
So the beam has to go one column further. A \ on row 2, column 4 turns it down, and a / just below it, on row 3, turns it left along row 3 and through the second gem. The third mirror is the one from step 1: a / on row 3, column 1 turns the beam down into the socket.

Solved. All three mirrors are used, both gems are lit and the beam ends in the socket. No other arrangement of three mirrors does that.

In the game that takes four taps: one for each / and two for the \, because every mirror goes down as / first. The result screen calls that the best possible, and a solve with no extra taps and no hints counts as flawless.

Things that help

Work from both ends. The laser decides how the beam starts and the socket decides how it has to finish, so usually only the middle is open.
Count turns. Every mirror is one turn and you have to use all of them, which rules out a lot of routes before you place anything.
A mirror does nothing unless the beam reaches it. Cells that no route can pass through can be ignored.
Look at the walls. On a lot of boards a wall is there to close off the short way round, like the one in the example.

Sundays have two lasers

Sunday is Twin day. There are two lasers and two sockets, and both beams take mirrors from the same tray. Either beam can light any gem, but each has to end in its own socket. The beams can cross, and a mirror turns whichever beam hits it.

The rest of the week grows in steps, from a 5×5 with two mirrors on Monday to an 8×8 with six on Saturday. The about page has the full table.

Hints, undo and the share card

Each board comes with two hints. A hint puts one correct mirror on the board and locks it there, and Undo and Reset leave it alone. Undo takes back your last tap, and Reset clears every mirror you placed.

When you finish, the share card shows one square per tap: dark when no gem was lit after that tap, yellow when some were, green for the tap that solved it, and a bulb where you used a hint. It shows how your solve went without giving away where the mirrors go.

On a keyboard, the arrow keys move a cursor over the board and Enter or Space taps the cell. U undoes, R resets, H uses a hint and ? opens the tutorial.

Missed a day

Every earlier board is on the past boards page. The last seven days are open to everyone, and older ones come with the Supporter pack. Playing one counts as an extra solve in your stats and never changes your streak, which only follows each day's own board.

Play today's board Past boards