I have a d20 that seems to be, well, remarkably lucky.* How can I determine whether it's really just luck, or whether the die is in fact unfairly biased?
*) Well, I don't, really. This is actually a spin-off from this question, which is specifically about determining whether a die is loaded. This one is intended as a more general question about how to detect any kind of bias in dice, since we apparently don't have one yet. I've posted my own answer below, but feel free to add more.