Unlike the similarly motivated French Defence, the Caro–Kann does not hinder the development of Black's light-squared bishop.
White can combat the Caro–Kann in several different ways, often gaining a space advantage; additionally, Black has less mobility and can lag in development.
The Caro–Kann remains a popular opening in top level chess, being employed by among others Alireza Firouzja, Vladislav Artemiev and Ding Liren.
More popular recently are variations with Black castling kingside and even leaving his king in the centre.
It has been played by and named after the first, seventh, and twelfth world champions Wilhelm Steinitz, Vasily Smyslov and Anatoly Karpov, but is now most commonly known as the Modern Variation.
The short-term goal of 4...Nd7 is to ease development by the early exchange of a pair of knights without compromising the structural integrity of Black's position.
Black has voluntarily opted for an inferior pawn structure and a practical necessity of castling queenside, while gaining dynamic compensation in the form of the open g-file for the rook and unusually active play for the Caro–Kann.
Viktor Korchnoi played 5...exf6 many times (including his first world championship match with Anatoly Karpov), and this line has also been employed by Ulf Andersson.
Black is waiting for an opportunity to develop his queenside bishop without giving up his d5-pawn: 4.Nf3 Bg4, often switching into a "French" structure after moves like 5.Be2 e6 6.0-0 Nf6 7.e5 Nfd7 followed by c5, Nc6 and Qb6.
[5] The variation that follows 1.e4 c6 2.d4 d5 3.e5 Bf5 has gained popularity after having previously been widely regarded as inferior for many years, owing chiefly to the strategic demolition that Aron Nimzowitsch (playing as White) suffered at the hands of José Capablanca in one of their games at the New York 1927 tournament.
[6] The Advance Variation has since been revitalized by aggressive lines such as the Bayonet Attack (4.g4) or the Van der Wiel Attack (4.Nc3 e6 5.g4), a popular line in the 1980s and later favoured by Latvian grandmaster (GM) Alexei Shirov, or the less ambitious variation 4.Nf3 e6 5.Be2 c5 6.Be3, popularised by English GM Nigel Short and often seen in the 1990s.
This line is considered to offer White a slightly better game and was tried by Bobby Fischer.
Some of the strategic ideas are analogous to the Queen's Gambit Declined, Exchange Variation (1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.cxd5 exd5), with colours reversed.
This system often leads to typical isolated queen's pawn (IQP) positions, with White obtaining rapid development, a grip on e5, and kingside attacking chances to compensate for the long-term structural weakness of the isolated d4-pawn.
is inferior as it is favourably met by 7.c5!, after which White plans on seizing the e5-square by advancing the b-pawn to b5, or by exchanging the black knight on c6 after Bb5.
3...e6 is probably the most solid response, preparing to exploit the dark squares via ...c5, though 3....g6 has been tried by Yasser Seirawan.
Related to the Fantasy Variation are the gambits 1.e4 c6 2.d4 d5 3.Nc3 dxe4 4.f3, originated by Sir Stuart Milner-Barry, and 1.e4 c6 2.d4 d5 3.Nc3 dxe4 4.Bc4 Nf6 5.f3 (von Hennig).
The Two Knights Variation 1.e4 c6 2.Nc3 d5 3.Nf3 (or 2.Nf3 d5 3.Nc3) was played by Bobby Fischer in his youth, but has since declined in popularity.
White's intention is to benefit from rapid development as well as to retain options regarding the d-pawn.
immediately runs into trouble after 5.Bb5+, when Black must lose a tempo and the bishop pair with 5...Bd7 (5..Nd7??
This variation is similar to the traditional Exchange Caro–Kann (in which playing Ne5 is one of White's goals) with the added benefit that the pin ...Bg4 has been sidestepped entirely.
After 3...Nc6, White may proceed with d4 and Bb5, responding to ...Qb6 with c4 (the Neo-Panov-Botvinnik Attack) and to ...Bd7 with Nxd7 to acquire the two bishops, or he may play in a Stonewall fashion with d4, c3, Bd3, and f4 in some order.