Slav Invitation

The Slav Invitation, 1...c6, answers the Zukertort Opening with a quiet pawn move that prepares ...d5 without committing to it at once. The name refers to the most direct transposition: after 2. d4 d5 3. c4 the game reaches a regular Slav Defense. Unlike 1...d5 or 1...Nf6, the move does nothing to stop 2. e4, so Black accepts that White may occupy the center with pawns and relies on the c6 pawn to support a later ...d5 strike.

The point of the move is flexibility. Black keeps the c8 bishop's diagonal open and can choose between a Slav-style chain with pawns on c6 and d5, a Caro-Kann setup against an early e4, or other arrangements depending on what White commits to. The drawback is that 1...c6 contests no central square immediately, which is why it is regarded as more passive than the main replies, although still sound and playable.

White's three most common answers lead to different kinds of game. 2. g3 is the most popular, heading for a kingside fianchetto in the spirit of the King's Indian Attack or Réti, where White delays central pawn decisions and Black usually builds a solid center with ...d5. 2. d4 is almost as common and points toward Slav or Queen's Pawn structures, with Black able to choose the timing of ...d5. 2. c4 takes the game into English or Réti territory, where Black can again aim for Slav-like positions. The engine also favors 2. Nc3 and 2. e4; the latter produces the same position as 1. e4 c6 2. Nf3, an early-knight line of the Caro-Kann Defense.

The line is a regular guest in online play, with roughly a hundred thousand Lichess games reaching it, placing it well inside the most frequently encountered named positions. White scores somewhat better than Black and draws are rare. The engine gives White a slight edge, in keeping with the view that Black has made a useful but modest move. Because the opening is largely a gateway to other systems, its theory is mostly the theory of whatever structure the players choose on the next few moves.