Is there a difference between "Destroyed" versus "Discarded"? My thought was that "Destroy" means to put out-of-play (i.e. no longer able to be used for that match) and "Discard" means put it in the appropriate discard pile for potential re-circulation and/or selection based on card ability. The issue came up with regards to Expatriette. When her "ammo" cards are used, the are "Destroyed" (which would make sense because it's ammo). This would mean that she *never* gets them back for that session (limited amount of ammo, for example).
Is this correct? Or, do "Destroy" and "Discard" *both* go back to the appropriate discard piel for potential re-circulation and/or selection based on card ability?
There are very few times something will be permanently removed from play, and not recirculated.. For those situations, the cards will explicitly say so.
Furthermore, you can't just discard or destroy something because you feel like it. You need a card to TELL you to, just like with basically any other effect in the game.
That doesn't fit, because cards in your hand are face-up and yet they get discarded when going to the trash, not destroyed. Also, sometimes a card/power will require you to "reveal the top X cards of your deck" and then discard one/some of them (for example Arcane Cadence or Research Grant).
Discard is always from your hand unless otherwise specified on the card. Thus Rivers of Lava are an exception and not the rule. Then again I feel the intent from those cards is clear.
Discard is from cards that are not in play. If an effect says to discard cards without clarification, it means from your hand; if it specifies that you must discard from the top of your deck, from revealed cards, et cetera, then of course you discard from there. Only cards in play can be destroyed.