Cactus Game Design Message Boards

For the sake of Philistine Outpost, when a new hero is presented against Goliath, does it count as a new attack?

Correct, it only activates "When you are attacked" due to the wording of the card.  It is not whenever a hero enters battle, only when an attack (rescue attempt or battle challenge) begins.

But yes, if Grapes of Wrath is used (and allows a new rescue), or if the hero uses The Long Day, Ambush the City, or similar abilities that allow another rescue attempt/battle challenge in that turn, then Outpost could activate again.