A 'drop" chip is exactly that, Don, a way of taking the house commission in a table poker game. They are used in card rooms which take their cut as a fixed amount for each hand, rather than a time charge (which is collected the players in regular chips). The appropriate amount in regular chips is removed from the pot and exchanged for a "drop" chip, which is then "dropped" into a slot above the house collection box. Hence, the sometimes odd amounts (such as the Top of the Vine $3.50 chip or the King Midas $3), which represent the house cut for a single hand. Many cardrooms will not sell drop chips, either off the table or out of the cage.