- "As long as the card has the potential to change the game state, you can begin the initiation sequence. Then, if an attack of opportunity is triggered and that changes the way you want the card’s effect to be resolved, so be it! That is perfectly legal. So, if you play Emergency Aid [with one damaged player or ally in play] and an attack of opportunity deals damage to your Guard Dog, you can then use Emergency Aid’s effect to heal the Guard Dog. You are able to do this because Emergency Aid did have the potential to change the game state before the attack of opportunity occurred (because Morgan was damaged). If, hypothetically speaking, no characters in play were damaged at the time you began playing Emergency Aid, then it would have no potential to change the game state and it would immediately abort the process before the card is even played. The same is true if you, for example, used A Chance Encounter to bring an ally back from your discard pile, and triggered an attack of opportunity that ended up defeating a different ally; you could then use A Chance Encounter to bring that ally back instead of the original one. "
When reviewing a card, one can't help to compare that card to other cards that do similar stuff. The "classic" healing options mostly are assets that use charges and require comming available actions to actually heal you. Compared to earlier in- and out of faction healing options, Emergency Aid offers something new. Well, 2 new things.
First, it let's you heal allies, which is nice . Second, it's an event, which means you commit 1 action to it instead of commiting an action to play it and then use more actions for each point you want to heal. When compared with the classic Guardian healing option First Aid, it becomes clear that Emergency Aid is a more "action efficiënt" way to heal. With Emergency Aid you pay 2 resource and use 1 action to heal you for 2 points, while with First Aid you pay the same amount of resources but have to use 3 actions to acually heal you for 2 points (1 for playing the asset and 1 action for every point of healing.)
Does that make Emergency Aid better? It al depends on your investigator and the deck you're playing. When used with a deck that is very "action heavy" or when you desperatly want to keep an important ally alive, you might like a healing option that is more action-efficiënt and heals allies. But when you're deck is less action heavy or you're playing an investigator with low sanity, you might prefer the ability to both heal physical damage and horror.
I really like these little nuances the designers are making in the different healing options and those make for very interesing deck building choices.
Of these options, Beat Cop (2), Guard Dog and Agency Backup are the ones that most synergies with Emergency Aid. Trusted can push some allies into the three health range, and of course all investigators have enough health to use the full effect.
But really, you two main uses for this card are in an ally focused deck, or in a Mark Harrigan deck to prevent the bad side of Sophie. Take Second Wind instead for all other cases; cheaper and with free card replenishment!