There are usually four players, but it is possible for a larger even number of people to play.
The players are divided into teams with two players in each team; the partners sit across from each other.
You can also use meaningless signals to confuse the opponents, but you are not allowed to have any signals with a meaning other than "I have four of a kind".
Cheating by using signals with other meanings is known as "table talk" and is penalised by loss of the game if discovered. This can be done at random or someone may volunteer. After everyone has looked at their cards, the dealer deals four more cards, one at a time, in a row face up in the middle.
The signal can be a body movement, a gesture or a hand signal, but words are not allowed (for example saying "elephants" cannot be used as a signal).
You can have several signals and can use more than one in a game.
After any hand any team is allowed to agree new signals; they may want to do this if they suspect that the opponents might have guessed some of their existing signals. When the last card has been turned up, any player can pick up one (or more) of the face up cards from the middle, add it (them) to their hand, and immediately discard a different card(s) face up in its place. A player who picks up more than one card must discard an equal number of different cards, to reduce their hand back to four cards.
If two players want the same face up card, the first player to touch it gets it.