From the Secret History, we know that Dark Ages was originally called War, but the German publishers wouldn't have any truck with that. It got me thinking as to what an expansion called "War" would entail. It couldn't just be random cards - expansions need a theme. So the theme here is that there's a new card pile called Conquests.
Conquest - Victory-Treasure - $0*
$1, 2VP
(This is not in the Supply.)
In order to get Conquests, you have to play Army cards, which are a new type sort of in the vein of Looters. The Conquest pile would probably have about 20 cards in it, and there would be a new end-game condition - the game can end when all the Conquests have been gained. Here are the card ideas I have so far:
Advisors - Action - $5
+1 Action, +$1
Look at the top three cards of your deck. Put one in your hand, discard one, and put one back on top of your deck.
Archers - Action-Attack-Army - $6
+3 Cards
Each other player discards down to three cards in hand.
Gain a Conquest.
Secret Agent - Action - $4
The player to your left reveals cards from his deck until revealing an Action that is not a Secret Agent. Play this as the revealed card - this is that card until it leaves play. If no Action was revealed, +$2.
General - Action - $6
+1 Action
You may play an Army or Attack card from your hand.
After playing that Army or Attack (or choosing not to), if this is the first time you've played a General this turn, while this is in play, whenever you play an Action, +1 Card.
Field Medics - Action-Army - $4
Gain a Conquest. Each other player gains a Silver.
Supply Train - Action - $2
+1 Card, +1 Action
If you've played 2 or more Supply trains this turn (including this), +$1.
You may play a Supply Train.
Heretics - Action-Attack-Army - $5
Gain a Conquest. Each other player gains a Curse.
Refugees - Action-Army - $4
Trash two cards. If you do, gain a Conquest, putting it in your hand.