I'm sorry for being late with this. I though I would have time between work and a dinner invitation, which I didn't, but now I'm here.
I probably won't do as thorough write-ups of the cards as some have done.
[added: Thorough or not, actually I wrote more than I thought I would.] It's not as if my views on these cards are more insightful than what others have said or are saying anyway. I am the judge though, so it matters what I think! So here are my comments on the 13 submissions are in the order they were given:
Swap (Event with 7 Artifacts) by spinefluI like the idea of minor startup differences. Sometimes they are not that minor, like if Jade Pendant is the only +Buy in the game, but then there is Swap, which might get used a lot, which can be fun.
This is in top four.
Clown (Action-Attack) by [TP] InfernoIt's inspired by Jester and is said to scale in multiplayer games like that does. I believe this would work fine for 2-Player as well though (like Jester does, incidentally).
Friends (Action-Attack) by majiponiIt's meant only for 4-player games which makes it too restrictive for this challenge.
Unite (Event) by AquilaI like how it reuses the Flag artifact in a way that will work fine both if Flag Bearer is or isn't in the game. (Even though it would need a reprint of Flag anyway in this imagined multi-player expansion.)
Introducing this new concept of Artifacts being
between players might become a problem with some (imagined future) card that does something general with players' Artifacts, but there is nothing like that now at least. (If this card stood on its own not reusing the Flag of course it could use an Artifact that affects you and your neighbour.
I like the Event having that low cost but no extra Buy, which can lead to interesting decisions on when to buy it for your single buy.
Pot Stirrer (Action-Duration) by NoMoreFunIt would be fun to get the positive effect from it! I think it would need an FAQ to make it clear what being
affected by an attack means, though. Are you "affected" by a Swamp Hag when it is played if you don't reveal Moat (or have Lighthouse out or ...) or are you not "affected" by Swamp Hag until you buy a card and get a Curse because of that? Also if there are no Curses left?
I think the first interpretation is the easiest, as when an Attack card is played is when the game "decides" who is immune and not, but I think some players would argue that they were not "affected" by someone playing Pirate Ship or Minion and not choosing the
attack option, or someone playing Legionary without revealing Gold, etc.
On the other hand I think that some also would argue that they were
not affected by a Young Witch if the revealed a Bane card, even if that's "just" part of following the instructions of the attack they were not immune against.
Story cards (Fragasnap)I really like that idea of having a property that may disqualify one player, and the winner is determined normally from the others! That can be really interesting, and is obviously not good for 2-player games, so extends the game in a direction not taken before, as I wanted to see!
That could have been a simple Landmark that disqualifies for example a player who has fewer Silvers than any other player, or who has more Victory cards than any other player, or who has a higher combined cost of all their Action cards than any other player, just to take three examples which I think could be interesting (even though I haven't though that much about them, and the last one may be a bit tedious to count).
The Story card concept looks interesting, but for me it looks a bit too complicated to be worth it, and as forkofnature (who commented on this) I'm also a VP counter player, so this uncertainness doesn't suit me.
Usurper's Crown (Artifact) by ArtlessHere is another option where one player can be disqualified. I would have liked to test this! But I suspect that often it will just stay out of play, because no one dares to take it. Wouldn't getting double the score of other players often be just too hard?
I wonder if it wouldn't be more interesting with a version which you
must take when gaining a Province. On some boards I guess it would lead to no one getting Provs, and players going for Duchies early.
Great Wall (Project) by grepThis looks solid. Personally I'm not that found of players being immune to attacks all the time, since I think attacks make the game more fun. (I would prefer it if playing Champion forced everyone else to discard their Champions, so that there was no eternal immunity even then.)
So it won't be a favourite of mine, but I think it's a good one.
Emissary (Action-Command) by GubumpThis is a card I really would like to play with a few times to see it in action. Actually it gets better and better in my mind just thinking about playing with it, when I notice how exciting that seems to be.
It might be slightly weak in what I wrote about exploring areas that would be harder to do for other C(SO)s, but I see that this would be weak in a 2-player game, so suitable for this imagined expansion for practical reasons.
This is in top four.
Agora (Landmark) by popsofctownI like the idea of it being good to be in the middle! So very multiplayer-y!
I suspect that 2 VP is too little to matter that much, though. When building an engine, each action card you need multiple copies of will open up the possibility for someone to get 2 VP from that pile. That shouldn't be that much of a deterrent to not get as many as you "need" of the card. Compare that with the 2 VP is what you get for
each card with Obelisk.
Flight of Fancy (Action) by forkofnatureThe 3+ spirit is there as forkofnature writes, but I don't think it adds anything significant that two
different players are naming the cards, instead of the same player naming both of them. So not enough multi-player-specific for this challenge for me.
Tithe (Action-Attack) by Something_SmartI like the general idea of an attack where it's up to the other players to somehow determine who will get the worst of it. That is also really a multi-player idea!
But since this is an attack, what happens if one or several players are immune against the attack, so there is only one player who discards a card? Does the card cost less to all the cards in the empty set? I suspect most of us say yes, at least if we are math/computer people, but I think it ought to be spelled out.
This is in top four.
Redistribute (Event) by anordinarymanSometimes catching up effects in games can be irritating in that they prolong games. But since this leads to someone gaining a good card I don't think it will. I wonder how often it would change how you build your deck, using more $3 and $4 cards. I think it can lead to interesting decisions!
This is in top four.
So which one is my favourite? I'll go with the last one:
RedistributeCongratulations, anordinaryman! You get to do challenge #54.