The event you are looking for is OnEnteredCombat. Use a charscript and include it in base or defaultbehavior.

Code
ON
	OnEnteredCombat(__Me, _)
CHECK "c1"
	CharacterIsPlayer(__Me)
Actions
	Do a thing for players


Alter as needed based on your needs.

Last edited by Sinistralis; 04/10/17 06:38 PM.