The Indian defences — 1.d4 Nf6 systems: Nimzo-, Queen's and King's Indian and their cousins.
Black lets White build a huge centre, then attacks it — often with a thematic kingside pawn storm while White plays on the queenside. Double-edged and thrilling, beloved by attacking players.
Black pins the knight and is ready to trade the bishop to damage White's pawns and fight for the light squares. One of the soundest and most respected defences to 1.d4.
White marries the Queen's Gambit to a kingside fianchetto: the g2-bishop rakes the long diagonal and squeezes the light squares for the whole game. A positional, low-risk weapon that has become a favourite at the very top.
The hypermodern partner to the Nimzo-Indian: when White avoids 3.Nc3, Black fianchettoes on b7 to fight for e4 from a distance. A rock-solid, positional defence built on light-square control.
A calm, reliable cousin of the Nimzo-Indian for when White plays 3.Nf3. The check on b4 develops with tempo and steers toward safe, sound positions with very little forcing theory to memorise.
White answers the King's Indian with the rugged 5.f3, building a huge pawn centre and preparing to castle queenside and storm the kingside. One of the most testing anti-King's-Indian systems: it invites a mutual pawn-storm race where both sides play for mate.
The main line of the King's Indian: White builds the big classical centre and Black strikes it with …e5, heading for the famous locked-centre races. After d5, Black storms the kingside with …f5–f4–g5 while White attacks on the queenside with c5 — one of the sharpest strategic battles in chess.
White forces the trade of Black's bishop for the knight with 4.a3, accepting doubled c-pawns in return for the bishop pair and a big pawn centre. A committal, ambitious line: White plays for a central pawn roller and kingside attack, betting the two bishops outweigh the structural damage.
White meets the King's Indian by fianchettoing too, blunting Black's dark-squared bishop and taking the sting out of the usual kingside pawn storm. A calmer, more positional approach than the Classical or Sämisch — White plays for a small, durable edge rather than a mutual attack.
White answers the Nimzo with 4.Qc2, avoiding doubled pawns and preparing to recapture on c3 with the queen, keeping a clean structure and the bishop pair. The Classical is one of the most respected main lines — a deep strategic battle over the centre and the dark squares.
White's most ambitious anti-King's-Indian: pawns on c4, d4, e4 and f4 build a huge, space-grabbing centre and threaten to roll forward. Double-edged in the extreme — if White's centre holds it's crushing, but it's also a target Black strikes at with …c5 and …e5 for immediate counterplay.
White meets the King's Indian's …e5 by locking the centre with 7.d5 immediately (the Petrosian approach), gaining space and steering into a slower, strategic battle rather than the sharpest Mar del Plata races. A positional way to blunt Black's kingside attack.
White meets the Classical King's Indian with the flexible 7.Be3, keeping options open between locking the centre (d5) and maintaining the tension. Named for Gligorić, it's a subtle, well-respected main line that tries to improve on the immediate 7.O-O or 7.d5.
White's most direct answer to the Classical King's Indian: after the centre locks, 9.b4 (the 'bayonet') slams the queenside pawns forward to attack before Black's kingside storm arrives. It's the critical, theory-heavy race where both sides charge the wing where the enemy king lives.