This is not very well known, but as size increases, dice roll more randomly. Not even manufacturers know this.
You're better off with 20mm die for preference, even though they roll loudly. 16mm are okay, 12mm are the least random.
The best material is plastic. Gemstone dice (including glass) chip without exception, and they're also all biased. Metal dice are quite a bit less random than plastic. Crystal Caste's crystal dice are too hard to read, but about as random as normal plastic polyhedrals.
I hope this advice helps people. It is actually very important for RPG gamers to know if you want a good game.
You're better off with 20mm die for preference, even though they roll loudly. 16mm are okay, 12mm are the least random.
The best material is plastic. Gemstone dice (including glass) chip without exception, and they're also all biased. Metal dice are quite a bit less random than plastic. Crystal Caste's crystal dice are too hard to read, but about as random as normal plastic polyhedrals.
I hope this advice helps people. It is actually very important for RPG gamers to know if you want a good game.