What Happens When Two Golf Balls Hit Each Other? Rule 11.1
The short answer
On the putting green: if your putt strikes another ball that was on the green, you get a 2-stroke penalty (stroke play) and the ball you moved must be replaced to its original position. Your ball is played from where it stops.
Off the green: no penalty. Both balls are played as they lie.
On the putting green (Rule 11.1)
When a ball putted from the putting green strikes another ball at rest on the green, two things happen:
- The ball that was struck must be replaced to its original position.
- The ball that was putted is played from where it stops — even if that happens to be in the hole (congratulations, the putt counts).
- In stroke play: 2-stroke penalty to the player whose ball struck the other ball.
- In match play: no penalty — the ball struck is simply replaced.
Why is the penalty only in stroke play?
In match play, your opponent would typically have removed their ball (conceding or marking it) before you putted. In stroke play with four-ball or groups, this isn't always practical. The penalty discourages players from carelessly putting when another ball is in the likely path.
How to avoid the penalty
Before you putt, ask any other player whose ball might be in your line to mark it. This is standard etiquette and costs nothing. If you ask and they don't mark it, and your ball hits theirs, there is no penalty to either player in stroke play — the struck ball is still replaced, and your ball played from where it stops.
The penalty only applies when: the ball that was on the green had not been marked, and you did not ask for it to be marked (or did not need to because it was clearly out of your path but your ball curved and hit it unexpectedly).
Off the putting green (Rule 11.1b)
If your ball is not on the putting green and strikes another ball at rest anywhere on the course (in the rough, on the fairway, just off the green):
- No penalty to either player.
- Both balls are played as they lie — from wherever they come to rest after the collision.
- If the struck ball was lifted and then you hit its marker, no penalty — replace the marker.
What if two balls end up in the same spot?
Extremely rare, but possible. If two balls come to rest touching each other after a stroke, you play the ball as it lies. If it's impossible to determine which ball is which, the balls are identified by any distinguishing marks.
What if someone else putts and hits my ball?
In stroke play:
- The player who putted gets the 2-stroke penalty.
- Your ball is replaced to its original spot.
- You don't receive any penalty.
In match play:
- No penalty to either player.
- Your ball is replaced.
Practical tips
- On the green, always mark your ball when there's any chance another player's putt might reach it.
- Ask others to mark before you putt if their ball is in your line or anywhere near it.
- The struck ball always goes back — it doesn't stay where it ended up.
- The 2-stroke penalty in stroke play is one of the most frequently incurred avoidable penalties in amateur golf.
Frequently asked questions
What if my ball hits the flagstick after hitting another ball? Two separate events. If your ball struck the flagstick while someone was tending it, there is a penalty for that (Rule 13.2b). If the flagstick was unattended, no penalty since 2019. But the collision with the other ball is still governed by Rule 11.1.
What if the ball I hit was already in the hole (like a ball someone left in the cup)? The penalty still applies — and you would replace that ball on the lip where it was. In practice, always remove your ball from the hole after holing out.
Does the rule apply if I'm chipping from just off the green? No. Only applies when the ball is putted from the putting green. If you're chipping from the fringe or rough, Rule 11.1b applies — no penalty, play both balls as they lie.
My ball hit another ball and went in the hole. Does it count? Yes. The ball in the hole stays in the hole (you've holed out). The struck ball is replaced to its original position. In stroke play, add the 2-stroke penalty to your score.
In Stableford, does the 2-stroke penalty often cost points? Yes. If you were making a par and get +2 strokes penalty, that hole goes from 2 Stableford points to 0. It's entirely avoidable — just ask the other player to mark.