If you just have to decide whether to go to a movie or stay at home, tossing an ordinary coin would suffice. If on the other hand, you’re trying to make up your mind if you’ll go to a movie, post an idea, go to the pub, play with the kids, visit a gallery exhibit or wash your hair, only a cubic coin
will do.

Made out of six, thin, aluminum alloy disks, this 5mm (0.2”) coin functions like other currency until its head is rotated 30 degrees counterclockwise. Then upon flipping the coin, the spring-loaded head opens on a tiny hinge to a right angle from the tail. From the head folds out a third disk and from it a fourth, etc. until the six sides ingeniously snap in place and interlock to build a hollow cube with circular sides.

Instead of heads or tails, the tossed coin lands on its head, tail, front, back, right or left side, helping you choose between two, three or six different things. Each side is also struck with one to six raised dots making the cubic coin a die. Two are all you need for a game of craps.

We know how to decide between any number of alternatives that are a power of 2 by repeated coin flips. To generalize to any number of alternatives, round up to the nearest power of two by adding dummy outcomes, and rerun the trial if a dummy wins.

So, for example, to select between 6 alteratives, select between 8 by flipping a coin 3 times; if the outcome is alternative #7 or #8, repeat the trial.