If a trauma card gets discarded (either because it says "do x then discard this card" or because its replaced by another card), does this card go back to the keeper (like mythos cards, pile faceup, when deck is empty, reshuffle, use as new deck), or does the card go into the box and out of game?

And a quick one: Is the attack action on the "Friend?" card mandatory or optional? IE., can the keeper use it to just move the investigator, and then not attack anyone (because no one is around?

1. it goes into the discard pile of trauma cards

2. Yes, attacking is optional... although I think it will be a rare situation where you wouldn't want to make the investigator take a shot at another one. If nothing else, for the hilarity of it.

Another question regarding the trauma cards, pliz.

If the Keeper plays a trauma card on an investigator that already has one of that kind, this last one is discarded (in substitution of the recently played).

But, what happens if the keeper plays a play-and-solve-its-effects card, and not a permanent one?

For example, one investigator has the card Kleptomania played on him, and then he suffers a Panic attack (I'm translating cards, I don't know the exact name, sorry). Does the investigator discard his Klepto card anyway, or keeps it since he doesn't keeps the Panic atack card? Thanx

I believe that the Klepto card is discarded into the pile of discarded trauma cards if any other mental trauma card is used on the player, even if the new card is then also discarded.

Yeah, I'd agree with discarding the original: most cards such as the new trauma are worded as "resolve the effects, then discard", suggesting that they have to be played as a normal trauma first, therefore discarding the existing trauma.

It looks reasoneable. We had that doubt in the spanish forum of the game since the rules are not very clear in that matter. Thanx