Barter by GubumpEvent ($5)
Gain a card costing up to $4 and a Silver.
This is fine, although I find it a little bit too simplistic. I can definitely see getting this when the $5s are not so good or when you're aiming to add engine pieces and payload and are trying to maximize your spending money and buys. It also makes otherwise unfavourable 5/2 splits a little better, which is nice.
Testify by Will(ow|iam)$10 Event
Gain all the Estates in the supply.
Considering this event will only ever be bought once per game, it actually changes up the endgame dynamic quite a bit. Normally when trying to cause a pileout, it's necessary to both have a high number of gains available, and still wiggle room to finish with a slight points lead. This event gives you the wiggle room gain wise, but requires you to hit a very high price point for it (which some gainer heavy decks can actually have difficulty with). It means that players will have to be much more mindful of a 3 pile ending, which I like. My one complaint with this is that it seems extremely frustrating to play with when Inheritance is also around, but that's a relatively small problem all things considered.
Atelier by czzzz Action ($5)
Gain two differently named cards costing up to $3, then non-Victory cards cost $1 less this turn.
The restrictions on this actually make it quite different from other gainers in the game, and I do think they are necessary for the card to be balanced as well. With the recent revelation of Tools from Plunder, I suspect this card would be pretty strong. I also think the $4 down to $3 was a good change as it now makes it much harder for this to gain itself (which is a much bigger deal for a $5 card versus a $4 inventor). Overall I quite enjoy this one.
Pandora's Box by faust$6
Night
Do this any number of times:
Gain a card that you haven't gained a copy of this turn costing less than the last card you've gained this turn.
This one looks very exciting and seems like it would have lots of synergies with other things that care about gains in a turn. I was going to comment about how I thought its ability to outright gain Provinces/Colonies was too strong, before re-reading it and realizing that it cannot actually do that (whoops
). With the way it's worded I can't come up with any problematic/overpowered interactions with anything (good attention to detail there), so I think this is an very solid entry.
League by xyz123Event
$8
Gain 3 differently named non-Victory cards that you do not have a copy of in play.
It's like a mini-Populate that can also gain Treasures or Night cards, which I think is pretty cool. I can see myself buying this 2 or 3 times on many boards for different purposes; first to add a lot of deck control, then to add some payload. I think the differently named restriction is definitely warranted here, otherwise you could gain things in triples and make it way too easy to avoid the second restriction on this. I also really like this one, so great work.
Foundry by kru5h Action-Reaction ($4)
Gain a Copper and card costing up to $5.
---
When you gain a card, you may reveal this from your hand to trash any number of Coppers from your hand.
Very clever design. Normally a $5 gainer that also self junks would be a bit on the weaker side and depend on strong trashing also being present. However, through this card's reaction it manages to alleviate this problem and simultaneously serve a secondary role in the deck, a reaction based thinner, which somehow isn't an idea implemented officially yet? I guess Hovel and Watchtower do something sort of like that, but you get what I mean. Nevertheless, this is another very strong entry that looks like a lot of fun.
Choices by BryGuyChoices ($6 Action)
Reveal cards from your deck until you reveal an Action card. Choose one: gain two copies of the revealed Action card; or gain a card costing $1 more and you may trash the revealed Action card. Discard all revealed cards.
There are two problems I see with this design. The first is that this is really, really susceptible to bad draw order. If you draw this at the end of a turn with no Actions left in your deck, then it's completely unable to do anything (Harvest also has a similar problem to this). A possible solution for this is to have it reveal something from your hand instead. The second (more minor) problem is that I don't see many cases when trashing the revealed card is going to be wanted (barring Ruins of course). I know it's an optional effect, but the card already has quite a lot of text as it is, so I think this part could stand to be removed.
Queen's Court by JW$5
Action
Choose one: gain a card costing up to $4 and a differently-named card costing up to $3; or you may play a non-Queen’s Court action from your hand twice.
I think this one is a little weak as is. I do think having to gain differently named cards is a good restriction to help prevent piles draining too quickly, but I think it could gain two cards up to $4 and still not be too strong. I also don't see a big reason for it not to be able to play itself, most Throne Room variants don't gain any extra tempo from playing themselves beyond saving an extra Action, which from my experience you'll usually have plenty of anyways (the obvious exception here is King's Court, as you get 9 card plays instead of only 6 otherwise).
Factory by NagdonAction ($7)
Gain two cards, each costing up to $4. If they are differently named, +1 Action
Like with earlier submissions, the bonus on double gaining with this card allows it to stand out a little bit from standard heavy gain decks. I do think this one is a bit too expensive at $7 though. I don't think it needs to be bumped all the way down to $5 as a non-terminal double gainer is really good and there are often going to be multiple engine components cheap enough to fulfill the differently named bonus, but I would try this one at $6.
Redistrict by 4estEvent ($0)
Once per turn: You may return a Province from your hand to its pile to gain 2 Duchies or vice-versa.
Another really unique and interesting event that impacts the endgame, this time for the other endgame condition. This will require you to pay very close attention to your opponents' decks to make sure they don't slip through with a win. Additionally, it's got a few neat synergies including Groundskeeper and things that care about gains like Haggler or Garrison. Another great submission!
Gemstone Mine by n_sanityTreasure ($5)
Gain two differently named cards each costing exactly $3.
While being non-terminal is nice, I think that this card feels a bit too restricted for a $5. Having to gain different cards that cost exactly $3 really restricts the engine pieces you can pick up with this, and with it being a Treasure you usually won't be able to use your new gains until the next turn. There's a lot of a different ways you could take this card, but I would suggest first removing one restriction at a time (the Treasure, the "exactly," the "differently named," or the "$3") and see which versions play best from there.
Dark Dealings by Xen3k$5
Night - Attack
Each other player may choose a non-Night card you have in play and gain a copy of it. They gain a Curse if they don't. For each card gained this way, you may gain a copy. If you don't gain anything, gain a Gold.
This card feels too political for Dominion in my opinion. The later player's decisions will be impacted by the decisions of the earlier ones (as you all obviously don't want your opponent playing DD to gain stuff, but better to make the others get cursed to minimize the damage) which I think breaks the whole "fairness" aspect of Dominion.
Summoner by Augie279Action ($4)
Gain a card that isn't a Province or Colony. Per $ more than $4 it costs, gain a Curse.
I really like the idea you went for with this one, but I do think it comes with 2 problems. The first problem is that, as others have pointed out, this card is extremely strong (too strong) in the presence of Potion or Debt cost cards. If it were this strong with only 1 card I would consider it a niche combo, but with the number of otherwise difficult to obtain cards that it can outright gain by itself, I think it's just too good. The second problem is that I find the wording of "card that isn't Province or Colony" to be awkward. I think that by limiting it to non-Victory cards costing up to $X, both of these problems can be addressed.
Trainee by Erick648$4 Action - Duration
Now and at the start of your next turn: If this is in play, gain a card costing up to $3.
Until then, when another player gains an Action card, you may exchange this for a copy of that Action card.
I think the Duration double gaining is fine (again, another concept I'm surprised hasn't been utilized other than Amulet) but I think the bottom portion is a bit too swingy early on, as this only has 1 turn of its two turn stay to activate it, and there's likely goin to be a substantial difference in your deck quality if you do manage to activate it. My analysis here may be off though, I found this card in particular really hard to evaluate.
Potluck by NoMoreFunAction - $4
+$1
For the rest of this turn, when you play an Action, if it's the first time you played a copy of it this turn, gain a Gold.
Similar to Choices from earlier, I think this card has too much dependence on when in your turn it is drawn. If you have to draw it at the start, you have the potential to gain upwards of 4 Gold with it, whereas drawing it at the end may lead to it just being a terminal Copper. In general though, I think this is going to be too strong for its price, as gaining even 1 Gold for $4 is going to be decent.
Forgers' Workshop by emtzalex$4 • Night - Duration
Now and at the start of your next turn, reveal a card from your hand. If it costs $5 or less, gain a copy of it.
At first glance, this looks extremely strong, until you consider the fact that in order to gain a $5 on the first turn, you must withhold playing something useful to keep it in your hand (or gain a Duchy, which can be useful for extra scoring potential later on). Failing to gain something significant on the first turn essentially turns this into a more restricted, non-terminal Importer. My point with these comments being, I think you've done an excellent job balancing out this card's high rewards with the necessary costs. Great submission.
Workshop Studentcost $4 - Action
Gain a card costing up to $4.
Gain a cheaper card than it.
I think the restrictions of the double gaining here feel warranted, as this card only costs $4 rather than $5 like a lot of the other submissions. This seems reasonably strong, but definitely not too strong. I think it's pretty good.
Collector's Items by sumrexAction/Treasure
4p
Gain up to three cards that don't all have the same name that have at least 3 cards in their pile, each costing up to 5 or 4p.
I think the original version of this that you posted (assuming the same card types) was much better. Gaining three different $5 cost cards already seemed too strong, but by lightening the other restrictions the card is even more powerful. Also, allowing it to gain itself I feel defeats the point of having a potion cost in the first place, as Potions generally act as a way to limit gains of something. Admittedly a fair number of the official Potion cards don't utilize it the best either, but consider University, which can't gain itself due to its Potion cost. In its current form I feel that spiking $4P will allow the first player to do so to snowball way too quickly. I would suggest limiting the number of gains to 2 and to bring back its other restrictions. I do like the Action/Treasure consideration though.
Inundate by arowdok$3
Event
Once per turn: Gain 5 Coppers. Set them aside. If you did, then at the start of your next turn, play them.
This looks wayyy too good in money strategies. Being able to pay $3 to receive $5 next turn makes it far too easy to hit $8 consistently (not 100% sure on this, but I think its quite likely you could achieve it every other turn starting on turn 2). This is also able to activate 9 times in a 2 player game, meaning that you shouldn't run out of Coppers in a non-mirror. I do like the concept of needing to take some junk to spike a price point, but in its current form this is definitely too strong.
Phew, that was more work than I was expecting. But now, time for the results!
Honorable Mentions: Atelier by czzzz, League by xyz123, Forgers' Workshop by emtzalex
3rd place: Redistrict by 4est2nd place: Pandora's Box by faust1st place: Foundry by kru5hThank you all for submitting and I hope you had fun! Happy Holidays!