Most tournaments we go to use the WKF ruleset.
It's officially no- or light-contact, but things get rough nearly every time, especially with less skilled competitors.
The rules are:
1 point for punches to head or body
2 points for punches to the back of the head or the opponent's back
2 points for kicks to the body
3 points for kicks to the head
3 points for a takedown or throw finished with a punch
2 minutes of fighting time for adults, match ends with TKO at an 8 point difference. The penalties would be a bit much to write here, the full rules can be found here:
WKF - RULES AND REGULATIONS