What is a 3-bet in poker? A beginner's guide

A 3-bet is the first re-raise before the flop. It’s called a 3-bet because the big blind counts as the first bet, the open raise is the second, and the re-raise is the third. A re-raise after that is a 4-bet.

Example

The cutoff opens to 2.5 big blinds. You’re on the button and re-raise to 7.5 big blinds. That’s a 3-bet.

Which hands to 3-bet

For value: A-A, K-K, Q-Q, A-K, and often J-J and A-Q against looser players.
As a bluff (advanced): hands like A-5 suited or K-10 suited. The ace or king makes it less likely your opponent has A-A or K-K, and the hand can still make strong flushes and straights.
At low stakes, keep it simple: mostly 3-bet for value. Many players call too much.

See starting hands and pocket aces.

What size?

In position (you act after them): about 3 times their raise.
Out of position (from the blinds): about 3.5–4 times their raise.

Facing a 3-bet

Fold most weak and medium hands you opened with.
Call with good hands that play well after the flop, such as pocket pairs or suited broadways, especially in position.
4-bet with your strongest hands: A-A, K-K, often Q-Q and A-K.

Why 3-bet?

You get more money in with strong hands.
You often win the pot right away.
You play against one opponent with the initiative, so your c-bets work better.

Learn positions first: 3-betting in position is much easier.

FAQ

What is a 3-bet in poker?

The first re-raise before the flop. The big blind is the first bet, the open raise the second, the re-raise the third.

What hands should a beginner 3-bet?

Mostly strong value hands: A-A, K-K, Q-Q, A-K, and sometimes J-J and A-Q.

How big should a 3-bet be?

About 3 times the raise in position and 3.5–4 times out of position.

What is a 4-bet?

A re-raise after a 3-bet.