Are dice copyrighted?
Yes. You will not be able to copy graphics on ‘special’ dice, but if all you want are generic D20s, etc., then there will be no problems.
Are D&D dice patented?
Can a die design be patented? The answer is yes they could be patented (the 100-sided die that looks kind of like a golf ball is patented). Game mechanics can be patented (look at Magic: The Gathering). A standard six sided die is not, as are many of the common dice configurations you know.
Can I sell dice?
While you unfortunately cannot sell DICE directly on Coinsquare, you can sell it on an altcoin exchange for Bitcoin or Ethereum and then use Coinsquare cash out to fiat currency like Euro or Canadian dollar.
Is roll20 free to use?
Play on Roll20® for Free.
What is the B on a D20?
B is a number to be added to the sum of the rolls. So, 1d20−10 would indicate a roll of a single 20-sided die with 10 being subtracted from the result.