What happens if your ball hits another moving ball?

No penalty to either player. If your ball in motion accidentally hits another ball in motion, both balls are played from where they come to rest (Rule 11.1a). The collision is treated as an accidental deflection — no replay, no penalty.

The situation

Two players hit their shots at almost the same moment and the balls collide in the air or on the ground while both are still moving. Or your putt rolls into another ball that is already rolling across the green after a previous stroke.

The rule

Under Rule 11.1a, an accidental collision between two balls in motion results in no penalty to either player. Both balls are played from wherever they come to rest after the collision. This situation is rare but covered clearly: the randomness of two balls meeting in motion is outside either player's control, and the rules treat it as they treat any other accidental deflection. No replays, no penalties — just play from the new positions.

Real example

On a par 3, you and a playing partner tee off almost simultaneously. The balls collide in mid-air, sending yours 40 yards right and theirs into a bunker. No penalty to either of you — play from the positions they landed in. You play from 40 yards right of the green; they play from the bunker.

What to do on the course

• Both players play from where their respective balls came to rest
• No penalty, no replay for either player
• If a ball can't be identified after the collision (both identical, no personal marks), try to reason out which is which from trajectory and landing area
• Mark your ball before the round — personal markings solve any identification doubt instantly

Applies in every format

Rule 11.1a works exactly the same in stroke play, match play, Stableford, or any team format. The collision is an accidental deflection regardless of the competition type — no penalty, no replay, play from the new positions. Your gross score in stroke play or the hole result in match play simply reflects where the balls finished after the collision.

Keep reading: match play · strokeplay

Exceptions that change the answer

• The player’s ball in motion hits another ball at rest on the putting green and both balls were on the putting green before the stroke (stroke play). → The player incurs the general penalty of two penalty strokes.
• The player’s ball comes to rest on any person, animal, or moving outside influence (including equipment) when the ball was played from anywhere except the putting green. → The player must take relief and drop the original ball.

FAQ

What if my ball hits another ball that's moving on the green?

No penalty. Play your ball from where it comes to rest. The other player plays their ball from where it comes to rest (Rule 11.1a).

What if both balls are identical and we can't tell which is which after the collision?

Use trajectory and landing area to reason out which ball is yours. If you genuinely cannot identify them, the Committee decides — but personal markings on your ball before the round prevent this entirely.

Is there ever a penalty when two moving balls collide?

Only if a player deliberately deflects or stops a ball in motion (Rule 11.2) — that's a separate offence covered in penalty for deliberately stopping a moving ball. A related but distinct breach is deliberately removing a loose impediment or movable obstruction to affect a moving ball (Rule 11.3) — see penalty for deliberately removing a loose impediment to affect a moving ball. An accidental collision between two balls in motion is never a penalty.

Do we replay the shots?

No. Both balls are played from where they come to rest after the collision. There is no replay provision in Rule 11.1a.

What if my ball hits a ball that was at rest, not moving?

That's a different situation. If your ball in motion hits a ball at rest on the putting green, you play your ball as it lies and the other player replaces their ball (Rule 11.1b). If it happens anywhere else, no penalty to either — you play your ball as it lies, they replace theirs.

Does it matter if the collision happens on the tee, fairway, or green?

No. Rule 11.1a applies anywhere on the course. Two balls in motion that collide are treated identically whether it happens off the tee, in the fairway, or on the putting green — no penalty, play from where they come to rest.

Can I replay my shot if the collision sent my ball into a terrible lie?

No. The Rules treat the collision as an accidental deflection, same as hitting a bird or a sprinkler head. You must play from the new position — there is no option to replay under Rule 11.1a.

What if my opponent's ball in motion hits my ball in motion in match play?

Same outcome — no penalty to either side. Both balls are played from where they come to rest. The Rules make no distinction between partner, opponent, or fellow competitor for accidental deflections between moving balls.