For example. A hero (with a weapon attached) attacks and destroys an enemy.

Scenario 1: Can I play two Foe-Hammers from my hand for the same single enemy that was destroyed?

Scenario 2: I play Foe-Hammer and draw 3 cards. Say the third card is another copy of Foe-Hammer. Can I play that one as well in light of the same enemy that was destroyed earlier?

Scenario 3 : I play Foe-Hammer and draw 3 cards. Say the third card is a Daeron's Runes. I play DR and draw 2 more cards the second of which is another copy of Foe-Hammer. Can I play that copy of Foe-Hammer in light of the same enemy that was destroyed earlier?

Scenario 1: Yes, provided you have two different weapons to exhaust (you have to pay the cost each time, and the cost of Foe-hammer is 0 resources + exhaust one weapon)

Scenario 2: I believe the ruling in this instance is "yes," which was an official ruling by a developer. You have not taken any actions

Scenario 3: No, can't do that. Once you play Daeron's Runes, you have taken an Action. At that point, the game state has moved beyond the 'enemy was destroyed' trigger which enabled you to play Foe-hammer, so it's too late to trigger a 2nd copy.

Scenario 4: You can also trigger multiple responses which have different effects. For example, after destroying an enemy, you can play both Foe-hammer and trigger the response on Blade of Gondolin.

For a bit more detail on Responses, here is the Response section from the online rules reference, and there reference itself is here: https://images-cdn.fantasyflightgames.com/filer_public/90/19/90191e4e-a341-4379-b398-5963b7a87ebf/mec01_online_only_rules_reference_for_website.pdf

Response Response abilities are labeled by the word “Response” followed by ability text. Unlike action abilities, which are resolved during action windows, response abilities may be executed after the specified triggering condition occurs, as described in the response’s ability text.

◊ It is possible for multiple responses to be executed from the same triggering condition.

◊ When two or more response abilities share the same trigger, resolve all response effects that use the word “when” before resolving response effects that use the word “after.”

◊ A response ability is always used immediately after its triggering condition has occurred and has been resolved. The first player always has the first opportunity to use an ability in response to a given triggering condition, followed by the next player, and so forth. Response opportunities for that triggering condition alternate between between players in this manner until all players have passed consecutively.

◊ Once the opportunity to react to a triggering condition has been passed by all players, further responses to that specific triggering condition cannot be used

Just a small addition to GrandSpleen excellent answer, for the Scenario 2 you still need a second weapon to exhaust on the hero to activate the second Foe-Hammer.

Thank you very much GrandSpleen. That was very helpful!

1 hour ago, GrandSpleen said:

Scenario 2: I believe the ruling in this instance is  "yes," which was an official ruling by a developer.

Correct.

I also have this nagging feeling that the ruling was later reversed, but I shall not be digging into that one.

It was clarified that cards that weren't on the table when the trigger occurred can't activate their Response to that trigger (e.g. character leaves play, quest card says "Forced: After a character leaves play, reveal an encounter card", and you reveal an enemy with "Forced: After a character leaves play raise your threat by 1; you don't raise your threat by 1). I didn't ask what that meant for the old ruling about cards you just drew, because I didn't want Caleb to take away our toys.

Edit: similar case where responses don't trigger: if a response to trigger X causes a card to acquire new text that also has a response to trigger X, the new response does not trigger. Example: A card with "Forced: When a character leaves play, attach to a hero. Counts as a condition attachment with the text 'Forced: when a character leaves play, raise your threat by 1.'" The first time a character leaves play, you attach the card as a condition, but do not trigger the threat increase.

A recent episode of CotR included a discussion over how Foe-hammer works with Glamdring.

I remember hearing that discussion and thinking “that ruling may have been reversed.” Seastan refers to a ruling that was on these forums a long time ago . Looks like I was remembering NathanH’s related question when I was wondering about a reversal.

Okay.

Just to mention: I lost the email unfortunately, but some time after this discussion, I asked Caleb to confirm Nate's old Valiant Sacrifice chain ruling ( http://www.cardgamedb.com/forums/index.php?/topic/1702-official-nate-rule-clarifications/#entry4469 ). Caleb reiterated that yes, you can indeed play a VS you just drew from a prior VS (even though the 2nd VS did not "see" the triggering condition).

I still find this weird, but hey.