Last Xmas I gifted my girlfriend a penguin trap boardgame.
Turns are based in a 4 options roulette, but it's uncomfortable, and the options are not clearly divided, so I thinked in 4 side dice, but I has no tetraedrical ones.
When I reclaimed a dice from an old and broken game which can't use in another game cause it has his own icons I thinked in a way to use on the penguin one. I only need to "nullify" two sides, so I made them unstable with a pair of screws.
Viewing the finished image is easy to imagine how it is made, but I made some photos.
Step 1: Erasing Previous Images
If you don't like the images on the dice, just sand a bit with a fine sand paper until they disappears.
Step 2: Making a Hole
choose any face and drill a hole in the center, until it pass through.
To trace the center use any 45° tool, per example, an carpenter angle tool, protractor or a folded corner of a paper .
Be carefull and don't tilt, it must be centered in both sides.
Step 3: Inserting the Screws
I used a shortened wall plugs for the screws to avoid damage the dice.
In the image I show the regular ones for comparation.
Step 4: Optional: Remarking the 4 Sides
Just to illustrate I put stickers on the rest of the faces to write on them
I will use coloured stickers in the final version to use the dice in the game.