When you enter a game, you must make a full buy-in for that particular game. A full buy-in at limit poker is at least ten times the maximum bet for the game being played, unless designated otherwise.
You are allowed to make only one short buy-in for a game. Adding to your stack is not considered a buy-in, and may be done in any quantity between hands.
A player who is forced to transfer from a broken game or must-move game to a game of the same limit may continue to play the same amount of money, even if it is less than the minimum buy-in. A player switching games voluntarily must have the proper buy-in size for the new game.