In four-ball stroke play two competitors play as partners, each playing his own ball. The lower score of the partners is the score for the hole. If one partner fails to complete the play of a hole, there is no penalty.

31-1. Rules of Golf Apply

The Rules of Golf, so far as they are not at variance with the following special Rules, shall apply to four-ball stroke play.

31-2. Representation of Side

A side may be represented by either partner for all or any part of a stipulated round; both partners need not be present. An absent competitor may join his partner between holes, but not during play of a hole.

31-3. Maximum of Fourteen Clubs

The side shall be penalized for a breach of Rule 4-4 by either partner.

31-4. Scoring

The marker is required to record for each hole only the gross score of whichever partner’s score is to count. The gross scores to count must be individually identifiable; otherwise the side shall be disqualified. Only one of the partners need be responsible for complying with Rule 6-6b.

(Wrong score — see Rule 31-7a.)

31-5. Order of Play

Balls belonging to the same side may be played in the order the side considers best.

31-6. Wrong Ball

If a competitor plays a stroke or strokes with a wrong ball except in a hazard, he shall add two penalty strokes to his score for the hole and shall then play the correct ball. His partner incurs no penalty even if the wrong ball belongs to him.

If the wrong ball belongs to another competitor, its owner shall place a ball on the spot from which the wrong ball was first played.

31-7. Disqualification Penalties

a. Breach by One Partner

A side shall be disqualified from the competition for a breach of any of the following by either partner:

Rule 1-3 — Agreement to Waive Rules.
Rule 3-4 — Refusal to Comply with Rule.
Rule 4-1, -2 or -3 — Clubs.
Rule 5-1 or -2 — The Ball.
Rule 6-2 — Handicap (playing off higher handicap; failure to record handicap).
Rule 6-4 — Caddie.
Rule 6-6b — Signing and Returning Card.
Rule 6-6d — Wrong Score for Hole, i.e., when the recorded score of the partner whose score is to count is lower than actually taken. If the recorded score of the partner whose score is to count is higher than actually taken, it must stand as returned.
Rule 6-7 — Undue Delay; Slow Play (repeated offense).
Rule 7-1 — Practice Before or Between Rounds.
Rule 14-3 — Artificial Devices and Unusual Equipment.
Rule 31-4 — Gross Scores to Count Not Individually Identifiable.

b. Breach by Both Partners

A side shall be disqualified:

1. for a breach by both partners of Rule 6-3 (Time of Starting and Groups) or Rule 6-8 (Discontinuance of Play), or
2. if, at the same hole, each partner is in breach of a Rule the penalty for which is disqualification from the competition or for a hole.

c. For the Hole Only

In all other cases where a breach of a Rule would entail disqualification, the competitor shall be disqualified only for the hole at which the breach occurred.

31-8. Effect of Other Penalties

If a competitor’s breach of a Rule assists his partner’s play, the partner incurs the applicable penalty in addition to any penalty incurred by the competitor.

In all other cases where a competitor incurs a penalty for breach of a Rule, the penalty shall not apply to his partner.