the action is automatically deemed a call whether or not the chip is large enough to otherwise qualify as a raise. In most casinos players are prohibited from handling chips once they are placed in the pot, although a player removing their own previous bet in the current round from the pot for the purpose of calling a raise (or re-raising) is usually tolerated. Otherwise, the dealer is expected to make change when required. Making change should, in general, be done between hands whenever possible, when a player sees they are running low of an oft-used value. The house dealer at most casinos maintains a chip bank and can usually make change for a large amount of chips. In informal games, players can make change with each other or with unused chips in the set. While this can prevent delays while players figure out change for a bet, casinos generally frown on or outright prohibit such practices to prevent players from surreptitiously "ratholing" (taking away and securing part of the stakes for personal use) and/or circumventing buy-in limits. Similarly, buying in for an additional amount must be done between hands (or, at least, done after a player has folded during the current hand) since players are not allowed to add to their stack during a hand. If buy-ins cannot and/or are not expected to be handled by the dealer it can take two or three hands for an attendant to bring another tray to the table. As described below, some casinos alleviate this issue by allowing cash to be deemed temporarily "in play" while staff fetches chips. Players who wish to always play with at least the buy-in limit will often carry additional chips in their pocket so that whenever they lose a pot they can quickly "top up" without inconveniencing the dealer or delaying the game. While having players buy chips directly from the dealer is seen as a convenience by some players, and can help deter players from exceeding buy-in limits, many players dislike this system because it slows down the game, especially if the dealer is expected to count large numbers of small denominations of chips. Also, many jurisdictions require all such purchases (or, at least, all larger transactions) to be confirmed (primarily to ensure accuracy) by a supervisor or other staff member, potentially causing further delay. To speed up play (and, by extension, increase the number