If you're playing with others, they can join your game by using the exact same room name. The room name can be anything you like (ex: 'joan's room'). To get started, enter a name for yourself (ex: 'uno-player-100') and a room name. Uno is multiplayer, and works for between 2 to 6 players. The first player to play all the cards in their hand wins the round, and scores points. In Uno, the goal is to be the first player to play all your cards.
