Open
To make the first voluntary raise of a betting round preflop.
In depth
In Texas Hold'em, an **open** refers to the first voluntary raise made during the preflop betting round. It signifies the initial aggressive action, setting the bet size for the hand and distinguishing itself from passive play like limping. Once an open occurs, any further raise is classified as a 3-bet rather than another open.
Chinese: 开池 (首加注)