There are 3 main reasons why you want to 3 bet. The same rule applies to the '4 bet' and the '5 bet' (It's basically just a shortened abbreviation for saying 'The third bet in the round').' The 3 bet most commonly refers to the time when you raise the pre-flop opening raise of your opponent'.The mandatory blinds count as the first bet, the open-raise counts as the second bet, and any raise following this will be a 3 bet. 3 bets can happen on any street, but this article will focus on preflop 3betting. A 3 bet refers to any time a player makes the third bet in a pot.This article will focus on pre-flop 3-Betting So what is a 3 bet in poker?