3D Connect 4

This game is based on Nanku from NestroGames, https://boardgamegeek.com/boardgame/341499/nanku.

The rules are very simple:

• Object: Be the first player to create a line of 4 of your color.
• Lines can be horizontal, vertical, or diagonal.
• Horizontal and vertical are defined as one face touching.
• Diagonal is defined as one edge touching. 
• If the colored cubes are only touching through one corner, it doesn't count.
• If a colored cube becomes completely obscured (there are no more exposed faces), it no longer counts. You must be able to see one face of each cube in the line of 4.

Placement Rules:

• White plays first by placing a box in any orientation (horizontally or vertically) in the play area.
• Each subsequent box placement must align with the imaginary grid defined by the first box placement.
• Each subsequent box placement must be adjacent to an already placed piece (ie: one face of the box must be touching a face of an already placed box).
• Each box must be fully supported (no overhangs).

That's it. Games can range from 2 minutes to 30 minutes. In my experience, the first few games will mostly stay on a 2D plane and finish quickly until players better understand what moves are good. Then, the tower will grow to multiple layers and games will take longer.

Printing:

Print 40 male cubes in one color and 40 female cubes in another color. High contrast colors are recommended (black and white, red and blue, etc.) Snap them together.

For storage, I folded a poster board into a "playing card" style box. I wanted the box to hug the playing pieces tightly and keep them from making a lot of noise when transported in a backpack.

If you would like to 3D print a box, there are a lot of parametric-style hinged boxes available. It might be neat print a rugged-style box and felt-line it.