This is a standalone sequel to the card-drafting, tableau-building classic 7 Wonders. The two-player variant that came with that game was adequate but not great. Clearly the designer (Antoine Bauza) thought so, too, because he took the theme, graphic sensibility, and basic ideas, changed a few key mechanics, and produced this intense yet elegant game.
 
Instead of passing cards back and forth, players choose cards from a central Klondike-style layout which changes in each of three Ages. Some of the cards are dealt out face-down and aren’t flipped over until they are “exposed”, which means players almost operate with some degree of uncertainty.
As in 7 Wonders, the cards represent buildings which add to both sides’ resource, economic, military, and scientific prowess. Each player now has up to four Wonders they can build (these are drafted before Age I), some of which let the player take an additional turn immediately--which can provide a nasty surprise for an opponent who was counting on being able to pick up “that” card next turn.
 
The game can end immediately if one player gets too far ahead militarily or scientifically, which means both sides cannot afford to fall behind in those areas.
 
All in all 7 Wonders: Duel is a game full of interesting and hard decisions every turn, and because it lasts under 30 minutes with experienced players it can be played several times in an afternoon. The sequel, Pantheon, adds a whole other layer of complexity which is a bit hard to assimilate at first but ultimately makes the experience even deeper and more rewarding.