Critical Role is a video actual play of Dungeons & Dragons 5th edition by a group of professional voice actors. The show is live streamed weekly on Thursdays on Twitch, and available for download and streaming afterwards on Twitch and YouTube. It is also available as a podcast on the Critical Role official site. Some episodes are also performed live (in-person) at events like conventions (including an annual appearance at GenCon).
The game is currently in its second campaign of D&D. The DM is Matthew Mercer, and the regular players are Laura Bailey, Taliesin Jaffe, Ashley Johnson, Liam O'Brien, Marisha Ray, Sam Riegel, and Travis Willingham.
Critical Role has featured games other than D&D for one-shots or mini-campaigns, including Vampire: The Masquerade, Honey Heist, Crash Pandas, My Little Pony: Tails of Equestria, Call of Chthulhu, Deadlands: Reloaded, and Monsterhearts 2.