From the rules :
Nothing says “evil” like blood sucking. A vampire can
chomp on any adventurer for 3 damage. Or it can eat
and run: attack any adventurer for 2 and then return
to the Monster Lair face up, ready to be used in a later
A vampire can not attack priests (but it doesn’t mind the taste of
paladins). If the party has only priests left, the vampire can not attack
I'm pretty sure David was right.
A Vampire can attack at each of the 4 round of the combat if you use the attack that deals 2 damage for the first 3 round.