"Kibitzing" gives anyone watching a card or tile game the option to see the cards or tiles in the hands of the players. It's possible in all of the games except Poker and Blackjack. Commenting on the content of players' hands is considered extremely bad form.

Each individual player selects whether or not to allow people watching the game to see his or her cards. Thus, you can be kibitzing a game, but only be able to see two of the four hands if two of the players have disabled kibitzing. Kibitzing can be a very useful way to learn how a game is played or to brush up on strategy.