Set card game is a game in which you try to find sets of three cards out of a board of twelve cards or more. Which cards form sets depends on the four traits that each card has:

Shape: oval, diamond, or squiggle
Color: red, blue, or green
Amount of shapes: one, two, or three
Shading: solid, hollow, or striped

The rule of thumb:

If you're not sure if you've found a set, just ask yourself, "Are there only two of something?" If so, then you don't have a set. Here are some examples:

This would be a set except that two of the cards are blue. If they were all blue or there was one of each color, you would have a real set.

Similar problem here: two of the cards are solidly shaded. If all three were solid or there were one of each shading, it'd be correct.

Starting a game:

If you want to play with friends, hit start a private game in the top left corner. You can use the URL of your game room to invite your friends.

If you want to get into a game quickly, hit join a public game. You will be placed into a game that will start as soon as three people are present. While the room fills up, you can warm up in an unscored practice game.

Click cards to build sets. To clear your current selection, click on any part of the board. Type messages and hit enter to talk to the other players.

Hints:

If you need a hint or don't see a set on the board (which can happen), use the HINT button. If the majority of players do this, the game will reveal one card of a set on the board. If there are none, the game will deal three additional cards.