Build Your Very Own LEGO® Puzzle Box

A puzzle box is an art form of unassuming splendor. At their essence, these crafty contraptions challenge solvers to discover a secret compartment. Box exteriors by the Karakuri Creation Group, for example, display unparalleled beauty and craftsmanship in the intricate yosegi patterns, beautiful wood colors, grains, and playful design. Meanwhile, the lack of any obvious seams, panels, hinges, or drawers makes these inconspicuous cubes delightfully difficult to solve. While wood puzzle boxes have existed for centuries, contemporary craftspeople have been utilizing different media, like 3D printers, to create similar boxes.

I, however, have found another means, using the most familiar building material of all: LEGO

In the past few years, my Lego puzzle boxes have caught the attention of the puzzle community, including influencers like Chris Ramsay (who recently solved my retro Mac puzzle box). Sales of Lego to adult consumers has quadrupled in the last ten years, and many of us have combined our love of the brick with our curiosity for mechanical tricks. So, let’s find our Zen by building a puzzle box using common Lego elements that will contain the following: a concealed drawer, a tool, and a chamber to hide the tool.

Lego Terminology

• A brick has studs on top and connecting tubes underneath, and measures about half an inch (1 cm) tall.
• A plate also has the same construction as a brick but is one-third the height. In other words, three plates stack to equal one brick.
• A tile is the same height as a plate but lacks the studs on top for a smooth appearance.
• The size of a piece is described by the number of studs along the short side followed by the long side, such as a “2x4 brick.” (Quick tip: You can make substitutes, such as two 1x2 plates in place of a 1x4 plate.)

Pieces You'll Need

When I design a puzzle, I usually start with the drawer.

A 4x4 plate will be the base of your drawer, and we’ll build up the walls using two layers of bricks around the perimeter of the plate. Notice how I place bricks in a symmetrically mirrored way. Also, I try to avoid aligning the seams between pieces on adjacent layers. We need the drawer to fit snugly yet slide freely inside the box, so we must finish our drawer with smooth Lego tiles.

For this build, we’ll use technic bricks (i.e., bricks with holes running through the middle) for the locking mechanism. I’m using a 1x2 technic brick on the rear of the drawer.

Constructing the Box

Next, let’s start on the box that will house the drawer. I’m using the following pieces:

We’ll use a 6x6 plate as the base. Next, we must provide the drawer with a smooth 4x4 tiled surface to sit on.

Let’s start by building up the walls of the box using two layers of plates. These plate layers ensure the bricks in the drawer will be in line with the bricks in the box. This will be important when we install our locking mechanism.

The next layer of bricks on the box includes two 1x6 technic bricks. These are not going to line up with the hole in the drawer.

Next, we add an important layer of bricks. The rear of the box has a hidden technic brick that includes a pin. This is our locking mechanism for the drawer. Also notice the small 1x1 tile on this layer. This forms the bottom of a hidden chamber that will house the secret tool.

Now we need two layers of plates. The first layer aligns with the tiles on top of the drawer. The next layer ensures our treasure inside the drawer won’t fall out if the box gets tipped over. Notice how a negative space is left in both layers for our hidden chamber.

Constructing the Chamber

One final layer of bricks is needed. This builds the hidden chamber to the required height to house the tool.

Lastly, the Box Top & Tool

We will build the top of the box as a separate sub-build using these parts:

The top of the box consists of four layers of plates and tiles. Start with the first picture and add additional layers as shown.

Carefully assemble the lid on the box. Ensure the negative spaces in the top and body of the box are aligned.

And now it’s time to build the secret tool with these three pieces:

Connect the tile and brick first, and then ensure the 4L bar (which is the length of four Lego studs) is inserted as far as it will go in the bottom of the brick.

This tool is long enough to dislodge the drawer via the holes in the back of the box. Put the tool in the hidden chamber with the flat tile on top. Full disclosure: I had to run the end of the bar on some coarse sandpaper to reduce the height of the secret tool ever so slightly. That way the tool sits at the desired height in the hidden chamber.

To complete the box, slide the drawer in place, and add one final tile to conceal the hidden chamber. This tile holds the secret to our puzzle. I mentioned earlier that Lego pieces have connecting tubes on the bottom. The 1x2 tile does not. This allows it to slide back and forth when connected to a single Lego stud. As a bonus, the height of the secret tool provides support for the sliding tile so it won’t fall into the hole in the box.

Words and images by Andrew Parr

When not playing with Lego, Andrew Parr regularly contributes to Games World of Puzzles magazine and writes escape room puzzles from his home in London, Ontario, Canada. Learn more about Parr’s Lego puzzle creations at his Etsy shop.