Index -> Interface -> Casual Games Lobby -> Joining Casual Games
Player-created games show up as Game Medallions in the main area of the Casual Games Lobby. Grey Medallions indicate games already in progress, while Light Blue Medallions indicate games waiting for players to join.
To join a game, simply click the Play button on the Game Medallion of a waiting game. This will bring up the Join Game dialog box.
Select which deck you'd like to use for the game. If you click the Browse Decks button, you can choose any deck file saved on your computer. If you use the dropdown button, you can quickly select one of your most recently used decks. If you have any Online Decks saved, these are also accessed by the dropdown button. The Deck Selection defaults to the last deck you used.
Once you have made your selection, click the Join button.