As theoretical as it goes -
I'm looking at
this page, and out of it comes the question of what resources are available for d&d players? And as a bonus question, even thou it's not really a resource as per the example provided, what method exists in d&d? The basis was always roll d20 and add a modifier (written in the first introductory part of the book), and latter was added a roll twice and discard one of the results. What can you think of?