Index -> Interface -> Casual Lobby -> Observing Matches and Getting Info on Matches

You can click the blue "info" button on any Match Medallion for information on the match setup and participants.

Any match with a red "eye" button on its Match Medallion allows observers. Clicking that button will take you into the match as an observer. You are able to chat with the players and watch the match unfold, but you will not see any hand contents or other secret information. You may stop observing a match at any time by right-clicking on the playmat and selecting Stop Observing.