Q. If a player runs out of golf balls during a round, may he borrow a ball from another player?
A. Yes. There is nothing in the Rules of Golf that prohibits a player from borrowing a golf ball from an opponent or fellow-competitor. A player who runs out of balls may get a new supply from any source, provided he does not unduly delay play (Rule 6-7) in the process. Although golf balls are part of a player`s equipment, the only type of equipment that the Rules limit the borrowing of is clubs Rule 4-4(Decision 5-1/5)