Empty your hand first. The round winner scores the card values left in every opponent's hand. The first player to reach the target wins the game: 300 points for up to 4 players, +50 for every extra player (10 players = 600).
Everyone gets 7 cards. Seats are shuffled every round. Decks: 1 for 2-4 players, 2 for 5-7, 3 for 8-10.
Play a card that matches the top card by colour, number or symbol, or play a Wild. Can't play? Tap the draw pile. If the drawn card fits you may play it, otherwise your turn ends. Draw cards do not stack.
Skip: next player loses their turn. Reverse: flips direction (acts as Skip with 2 players). +2: next player draws 2 and is skipped. Wild: choose a colour. Wild +4: choose a colour, next player draws 4 and is skipped.
You should only play it if you hold no card of the current colour. The next player can accept (draw 4) or challenge. If you cheated, you draw 4 and the challenger plays on. If you were honest, the challenger draws 6.
Two-sided cards. Light side: +1, Skip, Reverse, Flip, Wild, Wild +2. Dark side (pink, teal, orange, purple): +5, Skip All, Reverse, Flip, Wild, Wild +Colour. Flip turns every card in the game to its other side.
Wild +2: next player draws 2 and is skipped. Skip All: everyone else is skipped, you play again. Wild +Colour: next player draws until they get the chosen colour; it can be challenged like a Wild +4 (a wrong challenge costs 2 extra cards).
With one card left, press UNO (you can press it at two cards, before you play). If someone presses Catch before the next player acts, you draw 2.
If your last card is a draw card, the next player still draws before points are counted.
Classic: numbers = face value, Skip / Reverse / +2 = 20, Wilds = 50.
Flip: numbers = face value, +1 = 10, Skip / Reverse / Flip / +5 = 20, Skip All = 30, Wild = 40, Wild +2 = 50, Wild +Colour = 60.