So, almost all of the posts here are people's best attempts, usually playtested a few times and just in need of a little tinkering to get working properly. Anyone who has tried their hand at Dominion card design should know that most ideas...don't reach that stage. I've been keeping in a folder all of my failed or unbalance-able ideas that are nonetheless not ridiculous enough to throw into the "Really Bad Card Ideas" thread. I'm not especially looking for feedback on how to improve them as I've largely given them up for dead at this point, but if you've got any particularly inspired ideas feel free to chime in. Otherwise, maybe someone here will find something worth polishing up or, more likely, will at least get a laugh out of the attempts here.
Luck-based cardsShuffle-based cardsDuchess/Greed Mechanic TreasuresFragasnap's Greed expansion explores the interesting possibility space around the Duchess mechanic - cards that set rules for the games they're included in. One thing I'd noticed is that the majority of the Greed rule-cards explicitly slowed the game down; adding coppers on shuffling, increasing costs, trashing your cards on buying more expensive ones, etc, with very little in the way of cards that accelerate games instead. I've tinkered around myself with some ideas and while most of the Actions are workable enough to avoid a place here (
Silversmith for example), the Treasures are uniformly terrible. Here are a few.
Oddballs
Gambling Den: $4 Action. Roll a six-sided die. You may gain a card costing equal to or less than the number rolled.I have to admit that I actually still like the idea behind this, but my playgroup vehemently disagree. Luck is apparently not a fun element to incorporate more heavily than it already is in Dominion. If you're of a different mind, one widget to adjust if it proves too powerful is to make the card gain mandatory. But I never really got to playtest this much given the opposition to its inclusion.
Renovate: $3 Action. +$1, +1 Buy. Reveal the top two cards of your deck. You may trash one of them. If you do, gain a copy of the other if it is not a Victory card. Discard the revealed cards.Another luck-based card, but not as fun as Gambling Den. In practice it just ends up too swingy, doing nothing most of the time and occasionally turning a Copper into a Platinum. I can't really see a way to salvage this.
Dance: $2 Action/Reaction. +2 Cards. Whenever any player (including you) shuffles their deck, you may discard this. If you do, +2 Cards.Part of a little shuffle sub-theme I'd been working on. The theory being that it gets played for free some of the time, but is otherwise mediocre. Three major problems with it. First of all, it's impossible to balance for multiplayer. I tried adding a variable additional cost based on the number of players (which is a potentially interesting concept in itself that I haven't followed up on elsewhere) but in practice it was still just a cheap Lab most of the time with three or more players involved, which is kind of boring. Second, it requires you to keep track of something tedious and interrupt other players' turns for a minor effect. If someone else has an engine going that cycles through their deck and they're trying to keep count of the number of actions and card draws they have left, the last thing the game needs is someone throwing up their hand for a Dance mid-shuffle. And third, in practice I've found that people tend to shuffle their decks ahead of time if they're on the last card or two and know they'll be drawing past it during their next turn, just to save time. Dance makes that confusing and complicated, and doesn't provide enough pay-off for it to be worth it.
Sealed Chamber: $4 Action. +$3. You cannot buy or gain this until your deck has been shuffled twice.So terminal Gold for $4 is a little strong for an opener. Horse Traders gets close, but it's got a bit of a downside in that it can't bootstrap you to actual gold from your starting Coppers. Obvious solution: prevent the card from being bought in the first few turns. And it does actually kind of work. I think you might get away with just the first shuffle. But you remember how nobody ever buys Harvest? Yeah, same thing here. It's just...dull. The idea is nice though, I think.
Deed: $0 Treasure. Worth $2. While this is in play, you must first spend $2 on a Victory card before you can spend $ on anything else. In games using this, when you gain a Province you may gain a Deed.Soooo...yeah. $0 is probably the right price point for this. It's actually not terrible to get for free once you start greening in a Big Money strategy, offsetting your bloat with pseudo-silvers, but that's even more niche than Duchess, which is already a niche card. I could have tried bumping up the price and having it give $3, but it's still not really a very exciting card, and the interaction with Storyteller is weird to say the least.
Artefact: $6 Treasure. Worth $5. When you gain this, each other player may trash any number of cards from their hand. Gain five cards trashed this way. In games using this, add Platinums and Colonies to the Supply.This is just hilariously impossible to balance, and I tried because I liked the idea. Adjusting the cost, the value, the trash numbers, the gain numbers. No matter what you do, it's either too powerful or too weak in one of either duels or multiplayer. Maybe there's a perfect set of numbers out there for it, but I've kind of lost patience in trying to work out what it is.
Archivist: $5 Action. +1 Card, +1 Action. Starting from the top of your deck, set aside every fourth card. For each, choose one: trash it, discard it, or put it on top of your deck.A Lookout/Cartographer hybrid. It only really does anything in big bulky decks since it doesn't (or at least isn't intended to) touch the discard pile, and even then it's kind of a milquetoast card. I think it could be functional after some numbers-tinkering, but I kind of prefer custom Actions to do something *interestingly* unique on top of combining the five vanilla bonuses (cash, trash, cards, action, and buy).
Heirloom: $0* Treasure. Worth $3. At the start of the game put 8 tokens on the Heirloom mat. This costs $1 per token on the mat. At the start of each round, if no player bought an Heirloom during their previous turn, remove a token from the mat. Otherwise, return all 8 tokens.Wow this was an early attempt. The initial idea - a card that gets cheaper until someone buys it - isn't *terrible*, but there isn't an easy way of concisely and unambiguously wording it. The above was the best I could think of at the time, and even that required the introduction of the term "round" that would have to be explained in an FAQ equivalent. In practice, it doesn't work fairly. It's political, it requires notoriously forgettable end-of-turn attention to keep the tokens in order, and, worst of all, the wordiness of the bottom half means that the actual effect of the card can't be very long or interesting.
In short, unmitigated failure.
Granary: $4 Action. +1 Card/+1 Action. Set aside the top card of your deck face down on your Granary mat. If there are four or more cards on the mat, put them into your hand.This one was mostly an exercise in introducing information hidden from both parties. As a card, it's ok. Middle of the road. It makes for some occasional good mega-turns, but has a tendency of temporarily dismantling engines without telling you about it. It's more a victim of personal philosophy than anything else. Non-terminal $4 action cards are rare in Dominion for a reason, I think. The Terminal 4/Silver choice is one of the key components of the game in my opinion, and only a handful of cards break that - mostly Village+s, conditional cards, and the occasional oddball like Herald, Advisor or Caravan. It wouldn't be *terrible* for Granary to join those ranks, but I'm just not that enamoured of the card in the first place.
Assassin: $5 Action-Attack. +$2. Each other player with five or more cards in hand reveals all but one of those cards, and discards one of your choice.It turns out Pillage is a one-shot for a reason. Who knew?
Shaman: $3 Action. +1 Action. Reveal a card from your hand and the top card of your deck. If they don't match, +1 Card +$1.In practice this ends up just being a Peddler 90% of the time - the additional action isn't worth the time it takes to perform.
Well, talking about this junk has been cathartic at least. Feel free to chime in with your own monstrosities, or discuss any of the above, or just leave the thread languishing commentless.