In live games and low-stakes online, players still limp in (call the big blind only) preflop. "Someone limped—what now?" The short answer: iso-raise to play heads-up whenever you can.
Adjust sizing and range by opponent type (weak, sticky, aggressive, trappy). GTO uses limps only in narrow spots, but in real games limpers are a major exploit opportunity.
See also: Raise More in Poker, Exploitative vs GTO, and 6-Max RFI Ranges.
What Is a Limp?
A limp is calling the big blind as your first preflop action to enter the pot—also called "limping in." It is the minimum buy-in instead of raising first in (RFI).
In 6-max cash, limps happen when UTG through BTN acts first. Strong players today almost never open-limp from non-blind positions.
- Open limp: no raise yet—you call the BB to enter
- Over-limp: someone already limped and you call too (multiway)
- Limp-raise: you limp, someone raises, you re-raise (classic trap line)
This guide focuses on how to attack another player's open limp.
Why Limping Happens (Live vs Online)
Open limps are rare at mid-to-high stakes online but still common live, in home games, and at micro stakes online:
- Weaker player pool: want to "see a cheap flop" or hide strong hands
- Weak raise concept: calling feels like the default
- Multiway preference: more action, less folding
Rule reminder: preflop action cannot start with a bet (blinds count as a forced bet). A limp is entering by call, not raise. See What Is Preflop? for context.
GTO View: Why Strong Players Don't Limp
Open limping has clear downsides in theory:
- Range exposure: limp vs non-limp splits your range and gives information
- Equity leak: hands that would have folded to a raise get in cheaply
- Capped limp-call range: after you limp and face a raise, only the top of your range can 3-bet—you are capped postflop
- No initiative: you react to c-bets instead of leading
Solvers use limps mainly in special spots like tournament BB vs SB without rake. In 6-max 100BB cash, RFI is raise-only as the baseline.
When opponents under-defend blinds and over-fold to c-bets, raising (including iso-raises) carries extra value. See What Is GTO in Poker?
Core Strategy: The Iso-Raise
An iso-raise (isolation raise) targets one limper with a raise to play heads-up—the core counter to limps.
Iso-Raise Sizing Guide
| Situation | Size | Why |
|---|---|---|
| One limper, in position | 4–5BB + 1BB | Make limper's call expensive; encourage folds behind |
| One limper, sticky opponent | 5–6BB + 1BB | Build a bigger pot for value |
| Two+ limpers | 5–7BB + 1BB per limper | Raise the cost of multiway entry |
| Tight, value-heavy 3-bettor behind | RFI range or slightly tighter | Wide iso gets punished by narrow 3-bet/call and 4-bet lines |
| Bluff-heavy 3-bettor behind | At least RFI baseline (sometimes wider) | Exploit bluff 3-bets to maximize EV |
Iso-raising far wider than RFI makes you 3-bet fodder—that is what "keep RFI as a minimum baseline" means. Do not treat all 3-bettors the same: adjust based on whether their 3-bets are value- or bluff-heavy.
Example: BB = 10, UTG limps to 10. From CO, iso to 50–60 (5–6BB).
Which Hands to Iso With
Start from your RFI range for that seat and adjust:
- Heads-up likely: slightly wider than RFI if they fold often
- Multiway likely: favor pairs, suited connectors, suited Ax
- Value-heavy 3-bets behind: RFI range or slightly tighter
- Bluff-heavy 3-bets behind: keep at least RFI baseline; expand 4-bet range or slow-play traps
Adjust by Limp Player Type
Open limpers from non-SB seats are rarely strong. Split them into four types:
| Type | Traits | Iso | Postflop |
|---|---|---|---|
| Weak-passive | Rarely raises; check-folds missed boards | Wide, aggressive | C-bet often; take pots |
| Sticky | Hard to fold; calls with bottom pair | Larger with value | 3-street value with TPGK+; fewer bluffs |
| Aggressive | Many check-raises and donk bets | Tighter range | Check medium hands; bet strong hands big |
| Trappy | Limp-raises AA/AK | Polarized (include foldable hands) | Readable range—play situationally |
Weak-Passive Limper
The easiest to profit from. Iso wide with playable hands and c-bet frequently postflop.
With no 3-bettors behind, you can go much wider than RFI. If someone behind 3-bets often, adjust by 3-bet quality (next section)—not by default tightening.
Sticky Limper
Low fold equity—shift from stealing to building pots for value.
- TPGK+ (top pair, good kicker): value-bet three streets
- Second pair: often value-bet too
- Avoid pure bluffs—they call down with bottom pair
- Semi-bluffs: give up if the draw misses by the river
Aggressive Limper
Wide iso backfires vs frequent check-raises and donks.
- Keep a strong iso range
- Pot-control medium-strength hands—call more vs their donks and check-raises instead of betting blindly (bluff-catch mode)
- Strong but non-nut hands: value-bet while staying aware of stack depth
Lower c-bet frequency vs high check-raise rates—see Continuation Bet Basics.
Trappy Limper
Limp-raising AA/AK makes their range nearly face-up. Iso less often; when you do, use a polarized range.
- Polarized iso: 3-bet/call hands + raise-fold hands
- Over-limp with suited/connectors and small pairs to cheaply see limp-raises
- Fold vs limp-raise unless you can bluff-catch
Table Dynamics
When Someone Behind 3-Bets Often
"There is a 3-bettor, so always tighten" is wrong. Optimal iso width moves in opposite directions depending on 3-bet type.
Tight, value-heavy 3-bets
Vs opponents who 3-bet QQ+, AKs, etc., iso at RFI range or slightly tighter. Too wide and you face bad call/4-bet spots vs a narrow range.
Bluff-heavy 3-bets
Vs frequent bluff 3-bets with AQo, A5s, suited connectors, etc., keep at least your RFI baseline—sometimes iso wider.
- Expand 4-bet range: punish bluff 3-bets and build bigger pots
- Slow-play traps: call with AA/KK instead of iso-ing to invite bluff 3-bets
Shared floor: iso far above RFI is still exploitable vs both 3-bet types.
Multiway-Prone Tables
When callers behind are common, prioritize:
- Pocket pairs (set value)
- Suited connectors (straight/flush potential)
- Suited Ax (nut flush draws)
Reduce iso frequency with offsuit broadways (e.g. KJo)—they weaken multiway.
Multiple Limpers
Size up with 2+ limpers. Play tighter and favor hands that perform multiway (sets, draws).
Hand Examples: Iso Decisions
Three common spots:
Case 1: Iso-raise vs a weak-passive limper (CO)
6-max, 100BB. UTG+1 limps in for 1BB. You are on the CO. SB, BB, and others have not acted. UTG+1 often check-folds on missed boards.
K♠T♥ makes top pair or better often in heads-up pots and extracts value against a wide limping range. Weak-passive opponents fold to raises frequently—a 4–5BB iso-raise wins the pot uncontested often.
If they call, you have position (IP) and can keep c-betting, picking up check-folds on bad boards.
Calling invites multiway pots and hurts hands like K-T. You also surrender initiative preflop, which weakens your case for betting when they check.
Exception: if players behind you make many tight, value-heavy 3-bets, tighten to your RFI range or fold. Bluff-heavy 3-bettors need a different response (see below).
Case 2: Value-heavy iso vs a sticky limper (BTN)
MP limps. You are on the BTN. Villain rarely folds and often calls down with top pair— a "sticky" type.
A♦Q♣ is a strong value hand against a wide limping range. Sticky opponents do not fold much, so the main goal shifts from stealing the pot to building a big pot for value.
Use a slightly larger size (5–6BB) and value-bet three streets when you make top pair or better.
Calling keeps the pot small and under-rewards a premium hand. Against sticky players, avoid pure bluffs with no equity but bet aggressively with top pair+.
Case 3: Polarized iso vs a trappy limper
HJ limps. They have limp-raised with AA and AK before—a "trappy" type. You are on the CO.
Do not iso wide against trappy opponents. Enter with a polarized range—hands that can 3-bet/call + hands you can raise-fold. 8♥7♥ is on the raise-fold side: if they limp-raise (AA, AK, etc.), you fold for a small loss.
Mix in strong hands like AQo and JJ in the same iso range for balance. If they call, suited connectors make sets, straights, and flushes—and their range is so readable that postflop play is easier.
Calling behind risks entering a bloated pot out of position (OOP) when they limp-raise. Raise to take initiative and have a clear fold plan vs limp-raises.
Practice on nlh.poker
Use stats to check preflop habits relevant to limp defense:
- RFI (Raise First In): how often you raise into unopened pots—are you limping instead? (See preflop stats guide)
- PFR / VPIP: a small gap means less call-heavy play (including limps)
- 3-Bet: practice attacking iso-raises from behind—or defending when you iso
Drill: play NLH Quick 6-max, review hand history for "limper present—did I iso?" Check that PFR stays close to VPIP. App guide: nlh.poker full guide.
FAQ
Must I always raise vs a limp?
Iso is the default, but fold if the hand is outside RFI range or a tight, value-heavy 3-bettor behind forces a tighter iso range. Skip thin iso when you cannot price out multiway callers.
Should I ever limp myself?
In 6-max 100BB cash, avoid open limps; RFI with raises only. SB exceptions are covered in 6-Max RFI Ranges.
What if I get limp-raised?
Trappy types limp-raise AA/KK/AK. JJ and below, AQo, and similar hands may fold depending on size and stacks. If you iso'd with suited connectors, confirm you planned to fold to limp-raises.
Summary
- Limp: call the BB preflop to enter—often a weak-player tell in 6-max
- Default counter: iso-raise heads-up
- Sizing: roughly 4–6BB + 1BB; adjust for limper count and type
- By type: wide vs passive, value vs sticky, tight vs aggressive, polar vs trappy
- Your game: no open limps; raise first in
- 3-bettors behind: tighten vs value-heavy; keep RFI+ vs bluff-heavy; consider 4-bets and traps
Limps are rare in GTO but common in live/low-stakes pools—a major exploit. Combine exploitative thinking with raising more to attack limpers profitably.
