I am wondering in a 2 player game, what is the fewest number of turns each players could take to end the game. Lets assume both player are working together to make this happen and have prefect luck, so stacking your deck each shuffle is allowed.
You can end the game, even buying/gaining every single card in the entire supply, on turn 1! There are multiple possible ways to do this, but here is one:
- King's Court
I'm not going to go into all of the details here, because it gets quite long and complex, but the final step is to have bought a Travelling Fair, and a Villa to return to action phase. Then have a hand of:
King's Court, King's Court, Lurker, Lurker, Overlord
- Play King's Court (a)
- Play King's Court (1)
- Play Lurker (1), trash Overlord from supply
- Play Lurker (2), gain Overlord from the trash (put it on your deck because of Travelling Fair)
- Play Lurker (3), do anything, doesn't matter
- Play King's Court (2)
- Play Overlord(1) as Pixie, draw next Overlord, trash it to get the Boon
- Play Overlord(2) as Lurker, gain Overlord from the trash
- Play Overlord(3) as King's Court (a)
- Play King's Court (1)
That last step wraps back to the first... you have the same hand, same card on top of your deck, same cards in the trash. Except you have received a Boon.
With the infinite Boons, you will have received every Silver in the game from The Mountain's Gift, drawn them all into hand from The Sea's Gift, and gained all of the cards with The Earth's Gift.
The full details of this combo are written out in this forum post. All credit goes to Mith and other f.ds members.
There is also a video of this combo being demonstrated on Dominion Online:
So that particular combination requires a very convoluted setup and an extremely lucky starting hand, with the exact right Heirlooms. So here's a very short game that happened in a real, regular randomized game:
Turn 3, draw Quarry + 4 Copper. Stonemason -> 2 Villas (5 times). Stonemason -> 2 Trade Route (4-5 times). Win off Museum points
Empties the Villa, Stonemason, and Trade Route piles to end the game.
Details in this forum post.
While not as fast as GendoIkari's answer, using just villages, workshops and woodcutters from the base game it would be possible to have a game end very quickly.
- Using workshops to gain a free care costing 4 or less
- Using woodcutter for extra treasure and an extra buy
- Using village to draw cards and play an extra workshop or woodcutter
If both players used the effects of workshop and their treasure to only buy from these supply piles they would be able to rapidly deplete them.
I can get the game to end in 6.5 turns using just kingdom cards. This is not as impressive as the 3 turns posted by Gendolkari (posted concurrently with this).
Each player does the following (unless it specifies one player or the other):
Turns 1 and 2: buy Highway + Chapel.
Each deck is now 7 Copper, 3 Estates, Highway, and Chapel
Turn 3: Play Highway and 5 coppers (5 money, 2 buys, all cards cost 1 less). Buy Highway and Pawn
Turn 4: Use chapel to discard 3 Estates and a Copper
Each deck is now 6 Copper, 2 Highways, Chapel, and Pawn (and the next drawn card must be a Copper).
Turn 5: Play 2 Highways, Pawn (choosing +buy and +money), and 4 Coppers (5 money, 4 buys, all cards cost 2 less). Buy Port, Bridge, and 2 Pawns.
Each deck is now 6 Copper, 3 Pawns, 2 Highways, 2 Ports, Chapel (2 Coppers and a Chapel must be the next three cards drawn).
Turn 6: Play 2 Copper, 2 Highways, 2 Ports, 2 Pawns (choosing +draw and +buy), and Bridge (Chapel unused; 3 money, 6 buys, all cards cost 3 less). Player 1 buys 2 Ports, 2 Pawns, 2 Chapels. Player 2 buys 1 Port, 2 Pawns, 3 Chapels
The Port and Pawn piles are now empty and the Chapel pile has only 3 left. The top of each deck is 4 Coppers and a Pawn.
Turn 7 (player 1): Play 4 Coppers and Pawn (+1 card, +1 action), draw and play 2 Highways. Buy the remaining 3 Chapels. The game ends from 3 empty piles.