It works on a credit system that provides more Fast Queue games the more you're willing to play any role. You get four games (on top of the one you're playing) each time you play solo. Two-player parties earn two games each, while three-player teams earn a game each. Five-player stacks will always enter the Fast Queue, but they won't earn future credits.

Valve acknowledged that this is addressing a problem it partly created. The recently toughened matchmaking requirements for Ranked Roles might prevent wildly imbalanced teams, but they also leave players waiting longer for that one person who's willing to play a less exciting role. In theory, this both speeds up play and reduces the chances of your team having a glaring deficiency on the battlefield.