"Action Button" definition

A bet that must be posted, in a seven-card stud high-low game, by the winner of a scoop pot above a certain size, signifying a full bet (a blind raise, in other words), rather than just a call of the original forced bet. Any player who acts before the action button can only call the bring-in. The holder of the action button essentially raises blind, and then, when it gets back to those who have only so far called the opening bet, they can either call or raise. For example, if the low card normally must bet $1 in a $5-$10 game, and there is an action button out, anyone who calls the $1 is committing to bet $5 later. No one would call the $1 without intending at least to call the blind raise by the action button. Whether the action button acts in turn, or after everyone else has acted, depends on the card room.