Overlap
A wrong order at the instant the server contacts the ball. Front must be closer to the net than the back-row player in the same stack, and left-to-right order in each row has to match the rotation card. FIVB checks that one frame; after contact, run where you want. Overlaps are free points for the other team and a brutal way to lose a tight fifth in club play.
Example
The setter edges up early, is even with the front-row player, contact happens, R2 whistles the overlap. Free point.
Frequently Asked Questions
How do you avoid overlapping in volleyball?
Stack in your receive lines the way the coach drew them, take a half step back if you are not sure, then fly after the serve. If you can see the server, you can still be wrong, so teach your foot order on film, not vibes.
When are overlaps checked in volleyball?
Only at contact. That is why hitters can crash to the pin a millisecond after the whistle, but not a millisecond before.