I know that in a "normal" 6-sided die, there are norms about the numbering order (as mentioned here). My question is this: is there any standard way of numbering the faces of the 20-sided die? For example, is 1 always between 7, 13 and 19? (these are the values that I see in the die that I am holding at the moment). If so: can you see a reasoning?
Some reasoning would be the take further step the effort to make it fair; however, I don't have any rule in mind that will achieve this end.
Finally: if there is no standard, is there any set of standard ways? For example, I can't imagine anyone putting 2 just next to 1, right?
(this question may be asked about other die types as well...)