Simpler Rules: Rule 29

Rule 29: Foursomes 

29-1. General

In a foursome, during any stipulated round the partners must play alternately from the tee and alternately during the play of each hole. Penalty strokes do not affect the order of play.

 

29-2. Match Play

If a player plays when his partner should have played, his side loses the hole.

 

29-3. Stroke Play

If the partners make a stroke or strokes in incorrect order, such stroke or strokes are cancelled and the side incurs a penalty of two strokes. The side must correct the error by playing a ball in correct order at the nearest point, not nearer to the hole, to the position (or estimated position where appropriate) from which it first played in incorrect order, which avoids damage to the lie created by the playing of that ball.  On the tee, the ball may be re-teed. 

If the side makes a stroke on the next tee without first correcting the error or, in the case of the last hole of the round, leaves the putting green without declaring its intention to correct the error, the side is disqualified from the competition.