The following rules can be considered optional.
Charleston is often used in modern American Mah Jong. At the start of each deal, players exchange tiles with each other. First the player who is East (dealer) exchanges three tiles with West, then South exchanges three tiles with North, after which East exchanges with South, and West with North. Finally East exchanges with North, and West with Sound. Each player passes the total of nine tiles. Jokers, if they are used cannot be passed.
Normally Charleston is played at the start of every deal of the game, but some players prefer to use Charleston only in the last (North) round of the game.
Note: Some rules allow blind passes, where a player is allowed to pass back one or more of the tiles that were initially handed by another player (and appear face down on the board until the exchange is complete).
Sometimes the rule of Charleston is accompanied by the rule of Ding Dong. According to this rule, a further exchange of tiles can be done at East's request. This time each player passes only one tile to each of the other players. Ding Dong can be repeated up to three times during the deal.
Some players use an additional rule according to which each player places at the start of each deal a predetermined sum (usually 100 points) in a pool ("kitty"). The pool is collected by the player who succeeds to win the deal with a Pung hand (a hand that does not contain Chows).
If the winning hand is not a Pung hand, or if the deal ends in a draw, each player adds another 100 points in the pool as the next deal starts.
The kitty points, like penalties and bonus for winning the Goulash deal, are paid to the winner after all other point calculations and possible payment doubles (i.e., they are not doubled nor cut off to the limit).
Sometimes a special deal called "Goulash" is played if the deal ends in a draw. (Note that the Goulash deal is played only if the deal ends in a draw because of exhaustion of tiles, it is not played after an abortive draw (caused e.g. by faulty declaration of out; on the other hand, if a Goulash deal ends in an abortive draw, another Goulash deal is started without increasing the counter for successive Goulash deals.)
The Goulash deal is normally played by establishing a pool of extra points that are to be paid to the winner of the deal, and applying some special rules (e.g., it is common that no Chows are allowed in the winning hand).
After a Goulash deal is played, the deal normally passes and a regular deal is played, disregarding whether there is a winner or not and even if East wins the deal, but other options are also common (e.g., the rules might specify that a new Goulash deal is played until there is a winner, each successive Goulash deal increasing the bonus for winning the Goulash deal).
The etiquette for correct drawing and claiming of tiles may vary, as may the consequences for violating the etiquette. Basically the irregularities which have no effect on other players should have no consequences in friendly games. To avoid confusion, the players should agree on the etiquette and penalties before beginning the game.
In the following some common practices are listed: