Platoons
Cost: $6 (Type: Victory)
Worth (1) VP for every 5 different cards in your Deck that have the same name.
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Explanation:
If you have 5 Coppers, it's worth 1 VP.
If you have 10 Coppers, it's worth 2 VPs.
If you have 10 Coppers and 5 Silvers, it's worth 3 VPs.
If you have 10 Coppers, 10 Silvers and 10 Villages, it's worth 6 VPs.
I think $6 is the appropriate price. I couldn't have it cost less, because you could easily buy it just by stacking lots of Coppers and Silvers and rack up tons of points. At this price, at least, you 'll have to build a more decent economy in order to make it work. You can still stack lots of Coppers an Silvers, but when you start greening it will be harder to hit $6.
I think it's an interesting Alt-VP idea, because it contains elements from other existing Alt-VP concepts and also gives some new interesting ones.
Every card on the board can be worth VPs. You can add in Coppers, Silvers, various spammable Action cards of any cost; Gold gainers get an extra credit here; Junking attacks will probably not hurt you as much (which is not true for Looters); and you got another reason to grab some Estates and hunt down the Duchies.
While the "5" number may need a tweak, it happens to be the appropriate number when this Alt-VP card is contested in a 2-player game. Winning the Platoons split (and to lesser extend the Duchy split) is of great importance, as it will let you reach the "5-same-named-cards" threshold. In the same manner, when a Kingdom pile is contested, if none wins the split both players get to reach that threshold, and if someone loses it he gets denied the opportunity to do so.
What actually concerns me, is that this card may be too powerful if left uncontested in a fair amount of cases. I'm not sure about that though.
Anyway, I hope you like the idea.