The "single card engine" thread got me thinking about what other kinds of single-card engines are possible. I really like Minion (even though I get tired of playing them after a while), and so I was mulling over what might be similar but different.
When I realized we don't have a non-terminal "draw until X cards in hand"-type card, the rest came easily.
The problem with Library/Watchtower is that you can't spam them. Even if you threw on +1 Action, only the first one works; the rest become cantrips. But what if the card in question could also discard stuff, to set up the next one? So I came up with this, refined after a little playtesting:
Archivist
$5 - Action
+1 Action
Choose one: Draw until you have 6 cards in hand; or +$1 and discard 1 or more cards.
A single Archivist is roughly a Laboratory. Better if you can play Festivals and Fishing Villages first; worse if you draw it into your hand after your draw engine has started working.
But the idea of the card is to amass a critical density of them. With two in hand, you play one for the discard, throwing out the substandard cards in your hand so that the second one will draw a larger number of cards. With three or more in hand, you probably play for the draw first, so the second can discard more, so the third can draw more.
If your last Archivist draws an Archivist, just play the new Archivist as a cantrip. But if your last Archivist manages to draw two or more, you can repeat the cycle. The idea is that eventually you wind up with a 6-card hand with your best cards in it. Contrast with Minion, which earns more money as it goes but ends on a purely average 4-card hand.
It might sound like a lot of work to go to: a pair of Archivist is roughly a Cellar, after all, right? Well, not quite. Cellars use up spots in your hand. But because of the way Archivists draw, they don't really take up any space at all. So it's more like Cellars paired up with Laboratories.
I added the +$1 coin after playtesting showed it was still a little weak. But I think that did the trick. The bonus only applies to the discard part, because otherwise you don't get any benefit with that option other than to set up another one. Now you get benefit just by cycling in addition to the fact that you'll end the chain with your best cards in hand. It also allows you to get benefit from an Archivist if you only have one left, and your hand size is more than 6 cards. Play it, discard a Province, and you're up another coin.
It combos very interestingly with other cards. As I mentioned, Festivals and Fishing Villages and all the other cards boost a Minion engine will also boost an Archivist engine in the same way. It's also interesting when there are other drawers present, like Smithy or Rabble or Torturer, because you can try to time playing those to "up" points within the Archivist cycle to maximize benefit. That was probably the coolest thing I stumbled on. I really have to think that we'll get a non-terminal "draw until X" card in a future expansion, because even without the cycling piece of my card, the combos with other drawers are just too cool.
