Heads-Up (HU)
Also known as: Heads Up, HU, HUNL
A pot or table played between exactly two players. The small blind is the button and ranges are extremely wide.
Heads-Up (HU) is play between exactly two players — the purest form of poker. Every pot is contested one-on-one, so there is no folding-to-survive: you defend or attack constantly.
Key structural quirk
The small blind is the button. The SB acts first preflop but last on every postflop street — a huge advantage that drives correct strategy.
- SB/BTN open-raises or limps an extremely wide range (often 80–100% of hands at most stacks) and holds position postflop.
- The big blind defends very wide via blind defense — calling and 3-betting far more than in a full table.
Because equities run close and ranges are uncapped, aggression, steal frequency, and bluffing all spike. Every hand ends heads-up, so equity realization and relentless pressure decide the match. HU is the standard format for final-table deal negotiations and the last stage of every tournament.
Example
Both blinds 50bb deep. As SB/BTN you open A♠4♦ — a routine raise heads-up, where it's well above average equity, though it would be a fold from UTG at a full table. The BB defends with any two reasonable cards, and you realize your edge by being last to act on every postflop street.