The winner of the previous trick leads to the next trick.   Cards are played in a clockwise drection.

Declarer

If Declarer leads from the wrong hand, either defender can accept or decline the lead by saying so.   If the defenders disagree then the player next to play after the incorrect card has the final decision.   If the next defender plays a card then the erroneous lead is accepted.   If the anti-clockwise defender plays a card then it becomes a major penalty card.

If Declarer leads when it is a defender's turn to lead, the card is just withdrawn and play continues.   If the next defender plays then we just continue, the incorrect card has been accepted.

If a defender leads to a trick, and Declarer plays from the wrong hand, this card is deemed as played, and Declarer must also now play a card from the correct hand.   The incorrect card cannot be changed.

If Declarer leads from one hand and immediately plays a card from their other hand, this card is deemed played.   Either defender can now play next.

Defenders

The Laws are more strict for defenders playing at the wrong time, because they are giving information to a live partner.

If a defender leads out of turn then Declarer can accept this lead and play on.   Or they can not accept and the card becomes a major penalty card, remaining face up on the table.   The penalty card has to be played at the first legal opportunity, and if their partner comes on lead Declarer can impose lead restrictions.

If a defender plays out of turn during a trick, the offending card becomes a major penalty card.   Declarer can now also enforce restrictions on the offender's partner - they can demand they play the highest or the lowest card of the led suit; or if they are sure that the defender has no cards of the led suit, they can demand or forbid any other suit.

The 13th trick is automatically played in correct rotation.