What Is a 3-Bet in Poker? Definition + When to Use It
A 3-bet in poker is a re-raise after the initial raise. Learn what 3-bets are, when to use them, standard sizes, and common 3-bet mistakes — in 4 minutes.
What is a 3-Bet?
A 3-bet is the third aggressive action in a preflop betting sequence. The sequence works like this:
- 1-bet — the big blind (the forced bet that opens betting)
- 2-bet — the open raise (the first voluntary raise)
- 3-bet — a re-raise of that open raise
So when someone raises and you re-raise them, you have made a 3-bet. It is one of the most powerful tools in No-Limit Hold'em — it narrows the field, builds the pot with strong hands, and pressures weak opens to fold.
3-Bet vs 4-Bet vs 5-Bet
Each additional raise gets its own number:
| Action | What it is | Typical size at 100bb |
|---|---|---|
| Open raise | 2-bet (first raise) | 2-3bb |
| Re-raise | 3-bet | 9-12bb |
| Re-raise the re-raise | 4-bet | 22-28bb |
| All-in re-raise | 5-bet | all-in |
In practice, most hands reaching a 5-bet go all-in — the stacks run out before another raise is possible.
When Should You 3-Bet?
There are three main reasons.
1. Value 3-bet
You have a hand strong enough to want a bigger pot. Classic value 3-betting hands: JJ+, AK, AQs. You are expecting either to win preflop or to play a large pot with a strong hand in position.
2. Bluff 3-bet
You turn a hand too weak to call into an aggressor. The classic bluff 3-bet hands are suited Ax (A5s, A4s, A3s). They block the nut flush, have nut-equity when called, and remove value combos from the opener's calling range.
3. Isolation 3-bet
You want to play heads-up against one specific opponent — usually a weak limper or weak opener — and take position and initiative.
💡 New to 3-betting? Start with value only. Add bluffs once you can read villain's range clearly.
Standard 3-Bet Sizes
| Position vs opener | 3-bet size | Why |
|---|---|---|
| In position (IP) | ~3× the open | Position is already your edge |
| Out of position (OOP) | ~4× the open | Compensate for OOP disadvantage |
| Short stack (<40bb) | Just shove | No room to 3-bet and fold |
These sizes come from GTO solver outputs at 100bb depth. Deeper stacks allow slightly larger 3-bets; shorter stacks compress toward shove-or-fold.
Example
You have A♠5♠ on the button. UTG opens to 3bb.
- Fold → You miss a profitable bluff spot
- Call → You invite the blinds into a multiway pot and hand yourself a bad EV situation OOP vs UTG's strong range
- 3-bet to 10bb → You isolate UTG heads-up, take the initiative, and have both fold equity and nut potential when called
This is a textbook bluff 3-bet. It is profitable not because A5s is a strong hand, but because fold equity + position + nut blockers combine to make it a winning play.
Common 3-Bet Mistakes
- 3-betting too small → Gives opponents perfect pot odds to call with too wide a range. Size up to 3×/4×.
- 3-betting only AA/KK → Observant opponents fold marginal hands and you lose all value on the rest of your range.
- 3-betting OOP with weak bluffs → You will get check-called and outplayed postflop. While learning, reserve bluff 3-bets for IP spots.
- Auto-calling 4-bets → Most 4-bets are polarized (value hands + air). Call tightly: JJ+, sometimes AK, rarely anything else.
FAQ
What is the difference between a 3-bet and a 4-bet?
A 3-bet is the first re-raise of an open raise. A 4-bet is re-raising that 3-bet. 4-bet ranges are much tighter — usually QQ+ for value and occasional A5s-style bluffs.
How often should I 3-bet?
At 100bb cash depth, GTO 3-bet frequency is roughly 6-10% of hands, varying by position (tight from UTG, wider from the button). Tournament 3-bet frequency drops as stacks shorten — at short stacks, shoving replaces 3-betting.
Can you 3-bet from the big blind?
Yes. Big blind defense against an open is a mix of call, fold, and 3-bet. BB 3-bet ranges tend to be polarized — strong hands (QQ+, AK) plus bluffs (suited Ax, low suited connectors), with few marginal hands.
Is 3-betting the same as re-raising?
Yes, preflop. "3-bet" is the standard poker term for the first preflop re-raise. Postflop people usually say "raise" instead, though the sequence counting still works (a check-raise is technically a 3-bet if we count the blinds).
What is a "squeeze"?
A squeeze is a specific kind of 3-bet: re-raising after one player has opened and one or more players have called. You are "squeezing" the callers — they now have to fold, call much wider, or 4-bet. Usually none of these options are good for them, so the squeeze wins the pot immediately a high percentage of the time.
Going Deeper
This article covers the definition and core concepts of 3-betting. For complete 3-bet ranges by position, sizing across different stack depths, 4-bet defense, and drill-based practice, see our full guide:
→ The Complete 3-Bet Strategy: Sizing, Ranges & Defense
🎯 Practice 3-bet ranges live → VS RFI GTO Training