The scientific reason behind the “My dice hate me” phenomenon

I’m currently playing in a monthly M&M game in which I’ve experienced a lot of frustration due to die rolls: As someone who has a good grasp of probability, I understand that short-term observations (even over a half dozen game sessions) is very biased. However, over the last few sessions I had begun to suspect that the two D20’s I bring along (picked up from a dice bin at a con) consistently roll certain #’s more than others.  Now I think I know why:

Game Science Part 1

Game Science Part 2

Credit where credit is due:  I originally found these videos through a post on D20 Source.