I don't really play RPGs myself, but I have looking for recommendations for a nice set of RPG dice for a gift, and in my research I have come across several instances (in this sub and elsewhere) in which it is stated that dice with sharp edges and corners are more random, but no explanations as to why. This idea doesn't make inherent sense to me.

All else being the same, I can see that a die with rounded edges and corners would probably roll around more, but how does that make it less random? My initial thought was that, if anything, more rolling would actually make it more random.

My current thoughts, however, are that rounded dice are possibly most often the result of cheaply made dice; i.e. manufacturers round it off to hide the fact that the edges aren't nice and sharp to begin with. When dice are cheaply made they probably aren't super well balanced either, and a manufacturer who makes cheap dice is probably not going to worry about being really precise when rounding it off, which may lead to one edge be rounded more than another. I can certainly see how this would reduce the randomness of a die.

So, is that what people are referring to when they say that dice with sharp edges are more random? Are there any rounded dice of a quality that they would retain the same randomness as otherwise equivalent dice with sharp edges?

I'm not necessarily specifically looking for rounded dice, but this whole thing just caught my attention and now I'm very curious. Thanks.