The player who leads to a trick may play any card in his hand (unless he is subject to restriction after an irregularity committed by his side).
After the lead, each other player in turn plays a card, and the four cards so played constitute a trick. (For the method of playing cards and arranging tricks see Laws 45 and 65 respectively.)
In playing to a trick, each player must follow suit if possible. This obligation takes precedence over all other requirements of these Laws.
If unable to follow suit, a player may play any card (unless he is subject to restriction after an irregularity committed by his side).
A trick containing a trump is won by the player who has contributed to it the highest trump.
A trick that does not contain a trump is won by the player who has contributed to it the highest card of the suit led.
The lead to the next trick is from the hand in which the last trick was won.