The theme of this expansion is deck control, since in warfare, maneuvering is everything. The reason I'm making it is
mostly a thought experiment on balancing new cards, so please comment on whether the pricing/mechanics seem fair. I apologize in advance for way too many Victory cards/VP gainers involved. Also apologies if some of these cards have been invented before, since some of them are rather elementary.
Guerrilla
$3 Action-Attack
+$2
For each other player, you may choose a card from their discard pile.
They shuffle it into their deck.
Pillager
$3 Action-Attack
+$2
Each other player must gain a curse, or reveal their hand and discard all Victory cards.
Comments: Useless in some games.
Collapsed Mine
$4 Victory-Treasure-Reaction
$1
2 VP
When another player plays an attack, you may discard this.
When you discard this other than during a Clean-up phase you may reveal it.
If you do, trash a treasure from your hand. Each other player gains a copper.
Horse
$4 Treasure
$2
When you discard this during your Action phase, you may reveal it.
If you do, play it immediately.
Comments: Just for laughs, since it combos with Horse Traders and Stables.
Also it passes the Silver test
Consolidate
$4 Action-Duration
+1 Action
Set aside any number of victory or curse cards from your hand.
At the start of your next turn:
Draw a card for each card you set aside.
When you clean this up, discard the set-aside cards.
Comments: Like a Cellar, but if you can time the reshuffle this is good.
War-torn Village
$4 Action-Reaction
+1 card
+2 action
Discard a card
When another player plays an Attack card, you may set this aside from your hand.
If you do, then at the start of your next turn, +1 Card and return this to your hand.
Comments: Horse Traders variant, obviously. I'm afraid it may be OP without the discard, though now it may be a little weak.
Stockpile
$5 Victory
Worth 1 VP for each card name you have at least 5 of.
Comments: Likely very situational.
Counterfeit
$5 Treasure
+$1
The player to your left reveals their hand. If they reveal any treasures,
choose one, +$x where x is half the value of the chosen treasure, rounded up.
Comments: A venture variant. Silver, Gold, and Platinum give their proper value.
The dependence on the opponent's strategy may make this too unfavorable.
Retreat
$5 Action
+$2
You may trash an Action card from your hand. If you do, +2 VP tokens.
Comments: Likely to thrive in the same environment as with Vineyard.
Fortification
$5 Victory, Green-backed
4 VP
When you reshuffle, you must place Fortifications on top.
If a card is played that will reveal this from your deck,
you may place this in your discard immediately.
Comments: Late game Duchy alternative. The last condition might make the
drawback too weak in practice.
Siege(v1)
$5 Action-Duration
+1 card
+1 action
Next Turn: +1 VP token. During clean-up, if you played a Siege this turn, you may leave this in play.
Siege(v2)
$5 Action-Duration
+1 card
+1 action
Next Turn: +1 VP token. Whenever you play a Siege, +$1.
Comments: The idea is to pace your sieges. Which one do you like better?
Should it be $6 in either case? If one gets a slick engine with a majority of these, time will run out fast for the other players, which is thematically correct but of course that's no excuse for making it OP.
Strategic Position
$6 Victory
When you gain this, +3 VP tokens
1 VP
Capital
$6 Victory-Action
Set a Victory card from your hand onto the Island mat. If you do, +1 VP token.
2 VP
Comments: I guess it's kind of like taking Bishop and tacking on 2 VP, like Nobles and Harem.
You won't want as many though. If it's too weak, maybe:
Set a card on the Island mat: If it's a Victory card, +1 VP token
If it's a Treasure, gain a Silver
If it's an Action, gain an Action card costing at most $1 more than it.