Welcome to Interlock,
the hide the plug and socket puzzle!

Select pieces from INTERLOCK'S complete mathematical set of 12 building blocks to build 50 different shapes. Each 1x1x2 block is numbered and has one plug and one socket in a unique location. You build shapes by fitting each plug into a socket of the next piece. When the puzzle is solved, each plug will fill a socket, and the completed shape will have no plugs or sockets visible.

The Challenges: There are 50 shapes to build arranged easy to hard. Each challenge illustration lists the number of pieces needed to make the shape and the number of possible solutions. If you get stuck, we provide a multi-part hint for each challenge. If your plugs and sockets aren't connecting, a complete solution for each challenge is provided.

So what are you waiting for? Pick a block and start plugging!

-12 Building Blocks,
-Challenge Booklet with instructions and solutions.