UNO works brilliantly as a duel — the official rules make exactly three changes for a two-player game, all about what action cards do when there’s no “next player” but your opponent.
Everything else stays standard
Seven cards each, match by colour, number or symbol, draw one when stuck, call “UNO!” on your second-to-last card, and score the winner’s points as usual — see scoring.
A note on the rulebook
These two-player rules come from Mattel’s classic printed rule sheets (and are how the community plays head-to-head). The newest rule sheet simply omits the two-player section, so if your deck’s leaflet says nothing — this is the standard everyone uses.
Chained action cards are the whole game head-to-head. A Skip into a Reverse into a Draw Two is three turns in a row — entirely legal, entirely devastating. A few honest tips: