I believe it's what Gauss said. Roll20 started using the extra security step when there was an uptick in DDOS (denial of service) attacks on the site, within the past 1 year. It is an increased level of security on top of what the site normally has had in place. In my experience it doesn't take any longer than an extra 10 seconds, to get logged in, and then it doesn't come up again until you Log Out and come to log-in again, so in most cases it shouldn't come up more than once per game-session. Gauss said: I've also been getting that, mainly when I have two games in Roll20 open on the same browser. I expect it is a DDOS related protection.