Here are the submissions and my comments and my own rating - how much I would want to include each card into a game I'm playing (for a fun, balanced game). I recognize that my preferences are different than others, and others may like what I don't and vice versa, and that's okay.
I have copied the wording out of an image (for any that posted only an image), and have created a card image (for any that submitted text-only), just for consistency.
From pubby:
$5 Action-Duration
+1 Action
For the rest of the game, discard one less card from your hand during clean-up.
(This stays in play.)
At first, this looked way too strong. Then, realizing it only saves a card from hand (not from in play), it makes sense. It would definitely allow you to build a deck with a few more Action cards in it than you would otherwise, since it's easy enough to save one for your next turn (increasing the power of your next hand by adding to it rather than replacing a card from it by topdecking). As you said, the wording is unconventional, but is much more concise than alternatives - it just requires the clarification that at end-of-turn, you still draw 5 new cards (or 3 for Outpost) instead of drawing up to 5 cards in hand. Overall, this looks like a fun card to play with. Most of the time, I don't think there would be a need to buy a 2nd or more - unless you are regularly having too much money without extra Buys.
Rating: 7/10
From Aquila:
$5 Action-Duration
Gain 3 Silvers.
At the start of each of your turns for the rest of the game, you may trash a Silver from your hand for +2 Cards, +1 Buy and + $2.
(This stays in play.)
This card looks very difficult to judge. In some Kingdoms, it would be very powerful. In others, you would have to hope to match with those Silvers you gained and then it could be a dead card (at least it's set aside!) for the rest of the game. I like the idea, but I think it's probably too strong (most of the time) to cost $5. Alternatively, you could also take this idea, remove the "Duration" (and "start of turn"), and have it be a regular non-terminal Action card that gains a single Silver with the optional trash-for-benefit, costing only $4. I think that would be at least as fun as this Duration card.
Rating: 6/10
From mandioca15:
$5 Action-Duration
At the start of each of your turns, if you have no Debt tokens, +2 Cards, +1 Buy and set aside two Debt tokens. At the start of your Buy phase, take all Debt tokens set aside by this.
(This stays in play.)
In a way, this is like Wine Merchant - you need to have $2 leftover on some turn in order to be able to use it again. It would be great to be able to activate it every turn. But that would require a coin density in your deck of at least 1.0 in order to break even (the 2 cards you draw pay the 2 debt) - and obviously that's a waste of money to buy this card for that. But the benefit of the card is for spike turns - one great turn (start with +2 cards), then on a future turn with less money, pay off the debt to set it up again. Getting 2 or 3 of these in play would be huge, and because of that I think it probably needs to be pushed up to $6. But otherwise, I think this would be a lot of fun to play with.
Rating: 7/10
From Shael:
$4 Action-Duration
+1 Action
At the start of each of your turns for the rest of the game, you may gain a Copper to your hand.
(This stays in play)
This would be a great card to buy and play multiples. I think the changes you've made make it too strong. With a 4/3 split, I'd buy Silver and this just about every time. Then buy a couple more until I have 4 or 5 of them. I think by turn 8 or 9 most games, you'd have at least 4 in play which will guarantee a Province almost every turn. Either removing the +Action or (more likely) putting the cost back to $5 is probably needed. I like the concept of self-junking for benefit though. It really adds to the strategic element of the game.
Rating: 6/10
From grep:
$5 Action-Duration
At start of each of your turns for the rest of the game:
You may discard your hand for +4 Cards.
(This stays in play)
This is just one part of Minion - it's missing the Attack portion, and it doesn't give you an option for +$2 instead... but it does give you the mulligan option every single turn. I think this card could land anywhere from $4 to $6 without feeling out of place. Obviously the cheaper it is, the more likely someone would be to buy a second. The concept makes sense and would fit in the game, but it also doesn't "wow" me.
Rating: 5/10
From xmdata:
$6 Action-Duration
At the start of each of your turns for the rest of the game: you may trash a card from your hand.
While this is in play, the first time you trash a card costing $2 or more each turn, +1VP
(This stays in play.)
I like that the trash-for-benefit isn't too strong. It can trash Copper/Curse without benefit. It can trash Estates without losing the VP. Or it can trash early game Action cards that aren't needed anymore (such as weaker terminals). Trashing anything else for that +1VP probably isn't worth it, as it weakens your hand that turn. But it also feels like it would be available too late at $6 most of the time (terminal Action card with no benefit the turn it's played) - plus, I'd probably rather buy Gold than this at my first $6 most of the time. And if there are any other trashing cards available, I likely wouldn't buy this at all. I think your initial submission was too strong, but now this is too weak. It serves too niche of a market in its current form.
Rating: 5/10
From faust:
$5 Night-Duration
+5 Villagers
+5 Coffers
At the start of each of your turns for the rest of the game, lose a Villager or Coffers.
(This stays in play.)
Immediately, this card is only worth 4 Villagers and 5 Coffers or vice versa, since start of turn happens before you can use either. The +Villagers is only helpful when you have Action cards that need them. But I could see using up those 5 Coffers in the next 1 or 2 turns after playing the card (buy a Gold, a really strong Action card, or multiples if you have +Buy your next turn). The problem is, by the time you need some of the Villagers, they will likely be gone (maybe you'll be able to use 1 or 2 of them). And to make it worse, any other cards in the game that give +Villagers or +Coffers are significantly weakened by buying Mummer's Farce. Also, trying to buy a 2nd one makes matters worse as your stockpiles deplete even faster. The +5 Coffers is great. But I feel that the "Farce" in the name is too accurate.
Rating: 4/10
From spheremonk:
$6 Action-Duration
Place the top 3 cards of your deck face down under this. At the start of each turn: set aside a card from your hand face down; put a card from under this into your hand; put the set aside card under this.
(This stays in play.)
This looks like a great way to either balance out your hands, or intentionally create spikes from one hand to another. If you have too much money, set aside a Gold. If you have too little, set aside a Victory card and pull out money you've saved. If you have 2 terminal Action cards, set one aside. If you have no Action cards in hand yet, pull one out that you had set aside. It would be nice to just store Victory cards away in this, but that's what Island is for. And at $6, this has so much more potential. Plus, towards the end of the game, you can definitely start putting green cards under this. It would be great to have multiples too - like having multiple Crypts in play. Even better, Throne Room one of these (the Throne Room gets set aside with it for tracking, but then that $4 card is as valuable as this $6 card). The only complaint I might have is that the wording is a little awkward, but I think it has to be, to ensure you can't just keep your hand the same - to force the trade of cards.
Rating: 8/10
From JW:
$6 Action-Duration
At the start of your turn, you may trash a card from your hand. If you do, you may gain a differently-named card to your hand, costing up to $1 more than it.
(This stays in play)
This card is very, very strong. Compare it to Upgrade. Upgrade is a cantrip, same as this card (both leave you the same number of cards in hand before trashing). Upgrade forces a trash, whereas this leaves it optional. Upgrade gains the card normally (to discard pile) but this gains it to hand. Upgrade must gain a card costing exactly $1 more, but this card is "up to $1 more", which would allow you to turn a $5 Action card into a Duchy near the end of the game - something Upgrade can't do. Finally, Upgrade only works each time you get through your deck to play it, whereas Alchemical Factory works every single turn after you play it. As is, this card probably needs to cost at least $8. Otherwise, you need to take out a bunch of the options (force a trash, or gain costing exactly $1 more, or don't gain to hand, or even don't make the gain optional - trashing a Curse or Copper would get you back a Copper if it stays "up to $1 more"). It would be nice to have a card like this available, but it needs a few modifications for balance.
Rating: 4/10
From spineflu:
$5 Action-Duration
At the start of your turn, trash the top card of your deck. You may gain a copy of the trashed card.
(This stays in play)
This is effectively the same as "Reveal the top card of your deck. Discard it or trash it." other than the fact that your version works towards a 3-pile ending of the game. It feels very weak, but if it were $4 I think it would feel quite strong (being able to regularly open with it). I wonder about either doing the top 2 cards of your deck, or adding an option to put it back onto your deck instead of just trash/discard (maybe have the "gain a copy" be to the top of your deck"?) I do agree that "to your hand" was too powerful though. In general, blind trashing doesn't seem like a great idea. There is one Zombie that lets you do that, but it actually seems better than this card (other than the fact that you can't do it every turn).
Rating: 5/10
From anordinaryman:
$4 Night-Duration
If this is the first time you played a Voyage this turn, and the previous turn wasn't yours, then take an extra turn after this one. At the start of each of your turns for the rest of the game: gain a Copper.
(This stays in play.)
This is gained to your hand (instead of your discard pile)
I don't think I'm a fan of this card. It's a single-shot extra turn (likely on the same turn you buy it, unless for some reason you'd rather save it for later). Mid-game it's a way to turn a $4 hand into the possibility of a $5 or $6 hand. Towards the end of the game, it's a chance to turn a $4 into a Duchy or hopefully a Province. But as soon as you play it, you better hope you don't have many shuffles left in the game.
Rating: 3/10
From The Alchemist:
$4 Action-Duration
At the start of each of your turns for the rest of the game: Look through your deck and discard pile. Put a card from your discard pile into your hand, a card from your hand onto your deck, then discard a card from your deck. After all start-of-turn effects, shuffle your deck.
(This stays in play.)
I feel that this is way too strong at $4. Even with 1, once you discard a strong card from play (Gold, Goons, whatever), it comes back into your hand every turn. And with 2, as you mentioned, you can take any card out of your deck, put it into your discard, then into your hand. It either needs a much higher cost (at least $6, possibly more), or it needs some serious nerfing (though this would be hard to add, since there is already a lot of text). I also don't really like that it messes with the normal movement of cards so much - a small amount make sense (e.g. Harbinger), but not this much.
Rating: 3/10
From silverspawn:
$4 Action-Duration
For the rest of the game, when you shuffle your deck, +1 Coffers.
(This stays in play.)
I love the simplicity of this card. Its effect is not overpowering (which is needed from a $4 permanent Duration card), but it does seem appropriate - and tied to the name very well too. It will affect your strategy slightly, as you will want to be able to get through your deck faster (more draw, or more trashing, or both). There's a good balance that would be needed.
Rating: 9/10
From DunnoItAll:
$4 Action-Duration
For the rest of the game, at the start of each of your turns, look at the top card of your deck and either discard it or put it on the top or the bottom of your deck.
(This stays in play.)
I like the additional option to bottom-deck the card you look at. Even not in a Kingdom with Pearl Diver, it is a great additional option which isn't too complex but adds to the depth of the card. I also like how they can stack together (something to definitely consider at $4 cost), but only if you're not top-decking the card you look at. The real question is - how many of these would you buy at $4. You could definitely get a few if there are not other strong $3 or $4 cards in the Kingdom.
Rating: 8/10
From Lackar:
$5 Action-Duration
At the start of each of your turns for the rest of the game, you may trash 2 Coppers from your hand to gain a Silver or trash 2 Silvers from your hand to gain a Gold.
(This stays in Play)
This has some similarities to Trading Post. Trading Post gains the silver to hand (from trashing 2 cards, usually Estates and Coppers, not just Coppers), but this card is permanent, optionally acts on every turn, and doesn't take up an Action. The second option concerns me - yes, trading Silvers for Gold can be helpful, but you're giving up $4 buying power this turn to do it and have to wait a full shuffle to see the benefit. It would be nice if that Gold could be gained to hand or topdecked, though having the Silver gained to hand was probably too powerful (the initial version of the card). Maybe both gained cards could go to top of deck instead of discard pile? I'm not sure. I actually think I liked the initial concept better though - trashing 2 for a Silver to hand and if you didn't you gain a Copper. I guess if the Copper is gained to hand, then stacking 3 of these cards would guarantee you a Silver to hand every turn (which seems reasonable for 3 cards costing $5).
Rating: 6/10
From majiponi:
$5 Action-Attack-Duration
At the start of each of your turns for the rest of the game: gain a Silver to your hand, and each other player gains a Copper to their hand.
(This stays in play.)
This is like some previous submissions, gaining money to hand. But I think this one balances it fairly well, even combining an effective Attack with it (which temporarily helps others, then later hurts them). It's like playing a Council Room (which lets others draw a card), giving them +$1 this turn and even stacking with multiples (from the same or different players), unless a handsize attack hits. One potential problem is especially in games with more players, it will cause the game to end fairly quickly. Normally, Attacks slow the game down, but this one would likely speed it up - giving everyone more money on current turns. I do think the gaining of Silver to hand should be optional (and the Attacking conditional on gaining the Silver) though. This would actually work really well with Caravan City (previous submission above). One potential problem is tracking who is affected by which Gentleman cards when Moat, Lighthouse, or Champion are in play (since whoever is affected is determined at the time it's played but that remains true the full time it's in play... for the rest of the game).
Rating: 7/10
From Timinou:
$5 Night-Duration
For the rest of the game, if you have no Treasures in play at the start of your Night phase, +1VP and gain a card costing up to $4.
(This stays in play.)
This takes the concept of Devil's Workshop one step further - rather than just not buying a card this turn to gain a Gold, you now have the option every turn to gain both 1VP and a card (albeit only a $4 card). I think it makes more sense to "gain a card costing less than this" so when cost-reduction is available, you can't gain other copies of Elvenworks with it.
And I think you used the wrong VP logo (should be the token). But otherwise, I think this card fits perfectly with the Nocturne set. Great design.
Rating: 9/10
From gambit05:
$5 Action–Duration
At the start of Clean-up of each of your turns for the rest of the game: Exile a card from your hand. If you can’t, gain a Curse.
(This stays in play.)
This card requires perfect timing to pull it off. Ideally, you are Exiling all your Victory cards as they come in (and possibly Coppers if you haven't trashed them all yet), but you can't get one (or more) of these into play too early, or else you junk yourself. This is clever. And sometimes, you may end up taking that Curse anyway, as you need all your cards to buy that Province. Other times, you may give up buying a Gold, just because you'd rather Exile a Copper than take a Curse. This could be quite fun to play around with - and dangerous.
Rating: 8/10
From emtzalex:
$4 Action-Duration-Victory
At the start of each of your turns for the rest of the game, trash a card from your hand.
(This stays in play.)
Worth 1VP plus 1VP per Almoner you have in play.
Where Poet (previous submission, above) required good timing, I think this one is even more deadly if timed just wrong. It's use is combined between the two parts (trashing and VP), but if you try to take too much advantage of the VP, then you wreck your deck/hand. And like Distant Lands, this card isn't much use until it's played (though not quite as bad, because you could buy a whole bunch, then just put 2 or maybe 3 into play right at the end of the game, and it could be quite good if timed right). I like the VP-play with this, but I'm not sure I like the trashing (though I'm not sure how to balance the VP play without it).
Rating: 7/10
From NoMoreFun:
$3 Action-Duration
Gain a card from the Trash.
For the rest of the game, at the start of each of your turns, trash an Action card from the supply.
(This stays in play)
I might be missing something, but this card seems to not work. You gain a card from the trash once (on play), but you trash a card every turn from the Supply. This is helpful if you want to quickly get to a 3-pile ending. But just putting a card into play that helps with that, without doing much else, doesn't seem like a great design. I recognize that you've got the cheapest costing card design out of ~20 here, but I don't think it works.
Rating: 3/10
From fika monster:
$7 Action-Duration
For the rest of the game:
At the beginning of each of your turns, the player to the left chooses a non-Duration Action or Treasure card you have in Exile: Play it, leaving it there. You may trash that card.
At the start of Clean-up, the player to the left chooses a card you would discard from play this turn. Exile it.
(This card stays in play)
The most recent update to this card broke it. I think it was fine at $6 cost, with the person playing it choosing which card to Exile from play. You have some strength and some weaknesses. You could always put strong cards into Exile, but then you have nothing left in your deck to play. Or you could put a weak card into Exile (keeping good ones in your deck) but then you have a very weak start to your next turn. By letting the person to your left, choose both what you Exile and what you play the next turn - that just means they put in a Copper or a weak Action card. Although, now that I type that, it's not the end of the world to have that - and maybe comparable to the Hireling anyway? And by trashing each card that is used in Exile, you still have the option to play a single good Action or a single Gold one turn to make sure it's available in Exile for use at least one turn. If I thought about this one a bit more, maybe I'd like some of the final changes a bit more. But I don't like it much at the moment.
Rating: 5/10
From X-tra:
$6 Action-Duration
For the rest of the game, at the start of each of your trns, gain a Silver to your hand and at the start of each of your Clean-ups, trash a Treasure you have in play.
(This stays in play.)
Another interesting way to put a Silver into your hand each turn - just trash it at the end of your turn (though it's even better than that at first, when you can trash Coppers while you still have them). Unfortunately, I think this card is way too powerful at its cost. You could quite easily end up with 2 or 3 of them in play and basically guarantee buying a Province every turn. There needs to be some drawback.
Rating: 4/10
From Xen3k:
$4 Action-Duration
At the start of each of your turns for the rest of the game, you may discard a card for +1 Card. If you discard a copy of this, choose one: +1 Action; or +1 Coffers; or gain a Horse.
(This stays in play)
I like the simple sifting effect of this card. As someone else mentioned already, I think you would almost always want to play the next copy of it rather than discard for an additional benefit. It looks like a good card, but nothing unique or amazing stands out to me.
Rating: 7/10
Honourable Mention:Secret Stash by spheremonk
Snoop by DunnoItAll
Poet by gambit05
Runner Up:Elvenworks by Timinou
And the Winner is...Tax Collector by silverspawn
Congratulations. And thanks to all for the entries. It was hard work, but a lot of fun, to judge them.