Let's talk about my favourite Empires card, Archive!
I've played about 3 games with it so far (I don't get to play all that often) and it's been super interesting to me to see how decks turn out when using this card. We all know that non-terminal draw is super good, and Archive appears to be no exception, but it's very unique in how it does it and how your deck ends up playing. To me it has hints of Forum, Lookout and Haven all in one. I've never played Adventures so can't comment on comparisons with Gear.
Rather than ask when this card is good for your deck, it's probably easier to ask when it isn't good. I feel like you wouldn't want to play Archive under the same scenarios when you wouldn't want to play Lookout or Haven, times when you want to play every card in your deck and can't take the risk on having key cards be stored away for an extra turn. Would having an Archive draw 3 Wandering Minstrels make you happy or would it be the death of this turn and the next one? Given Archive costs 5, you'd likely just never buy one in the first place, too much good competition at that price point.
But not every engine is super strong, right? Sometimes there's no trashing, or no other decent source of draw. The latter case is particularly interesting, as with only a small number of Archives it's really easy to "draw" your deck, except most of it is actually sitting aside on the table underneath your Archives and Crowns/Thrones. If you play a lot of them on one turn, you end up with this cool effect of having almost no cards left, followed by a really strong turn, and then suddenly your deck is back to being massive and your turns throughout the game play totally differently from each other. I mentioned Forum earlier because when you play lots of them you end up reaching through your whole deck and can find and play your key card, it feels like super strong filtering even though all the cards you skipped are heading straight for your hand on your next few turns. I initially thought it would be tough to play a key card often in an Archive deck because of the fear it would be set aside by your Archives all the time, but it's really not as big an issue, just pull it into your hand straight away and you might even play it again next turn because you deck is super thin for a turn.
I'm still undecided if it's a good idea to play loads of Archives all at once though. The super good turn you have the turn after you play a load is amazing, but then two turns later you shuffle and your deck is enormous and the sudden shift to having these comparatively much worse turns is pretty jarring. Maybe getting some generally all-round good turns by playing one Archive a turn is better. If an Archive finds another Archive and two mediocre cards, is it better to pull that Archive now, or wait until next turn? I just don't know!
Perhaps Archive is the ultimate card for a Good Stuff Deck. You're not planning on playing your cards every turn but once every 2 or 3 turns is fine. Its easy to draw while avoiding terminal collision, or to match two cards together like Legionary/Gold, or Treasure Maps (barring the nightmare scenario of both being drawn by the same Archive). Yet you're also not hurt by getting some spares if you want to play them more often, and so you can end up having pretty good turns a lot of the time without needing very many support components at all. Archive essentially does sifting and draw at the same time.
A small side note, my first Empires game also had Castles and they rock with Archive. Especially Opulent Castle. Just wait to pull all of your victory cards into the same hand as Opulent Castle, and then discard them all for two coin each. I might even buy a Secret Chamber if one was available with Archive, having multiple types of income stream in your deck works fine with archive, on one turn you pull your treasures, and then on the next you pull your junk to trash/discard for benefit.
I don't really know where I'm going with this post. I just wanted to talk about Archive. Hooray Archive!