I bought these to switch-in in place of other dice and then put into a spectator's hands, with some sort of line like "Did you see me cheat you? If you look at the dice closely you can see that they're crooked."

That said, these are very cheaply made. I bought two sets. All four of the dice have an air bubble visible inside them. Not a big thing in what are gag dice, but an indication of overall poor quality manufacture.

The bigger issue is that they not uniform in size from one package to the next. One set that I received is approximately 1" on a side. (Since they are not cubes, no face is has the same dimensions as any other.) The other set is closer to 3/4" on a side. This, actually, I prefer as it is a more comfortable size to palm. If I could be assured of getting the smaller size I would order a few more pairs.

These are fine for board games or general use but I would avoid using them with magic. Brcause they are so bizarre looking they attract suspicion so no-ones going to believe that they are fair and normal dice.

These dice are lovely. They were dramatically different sizes, which just adds to the absurdity. As a bonus, the biggest face of the small die lines up almost perfectly with the smallest face of the large one. So I can stack them into a flat-topped pyramid, heck yeah!

Very crooked, just as advertised. 5 stars!