3-Bet

Also known as: three-bet, 3bet, reraise

The third bet in a preflop sequence — a reraise over an opener's RFI (blinds count as bet one, the open as bet two).

A 3-bet is a reraise of an open: the big blind is the first bet, the open-raise the second, your reraise the third. Modern 3-bet ranges come in two shapes. Out of position (e.g. blinds vs a BTN open) the solver favors a polarized range — strong value (QQ+, AK) plus low-equity bluffs (suited wheel aces, suited connectors, some offsuit blockers) — because you can't realize equity well with marginal hands OOP, so flatting them is better than 3-betting. In position (e.g. BTN vs CO) ranges shift toward linear/merged, adding strong-but-dominated hands like AQ, AJs, KQs and mid pairs that play fine as a raise.

Sizing follows the same logic: OOP 3-bets are larger (≈3.5–4× the open) to charge the caller and protect a polarized range; IP 3-bets are smaller (≈3× or less). 3-bet bluffs lean on blockers — an ace or king in hand reduces the opener's 4-bet/continue combos.

In tournaments, ICM and risk premium compress light 3-bets near the bubble because getting it in light costs more in equity than chips.