Chess Openings on Mainline

Mainline trains 28 chess opening families, each broken into engine-verified modules you drill move by move. Choose a repertoire and master it line by line, with plain-English explanations of every move.

Danish Gambit: Hand Black a pawn or two, on purpose. Both bishops swing onto long diagonals, aimed at the king.
Englund Gambit: Throw a pawn at White's queen-pawn opening and lay a queen-check trap. Natural-looking replies walk right in.
Vienna Gambit: Sacrifice the f-pawn to blast Black's kingside open. A sharper cousin of the Danish.
Traxler Counterattack: Sacrifice the bishop and chase the king into the open. Plenty of these lines simply end in mate.
Stafford Gambit: Hand White a pawn and pour your pieces out while they're still sorting themselves out. A minefield made for blitz.
Scotch Game: Skip the slow Italian and crack the centre open with the d-pawn. Sharp, tactical, your kind of game.
King's Gambit: Toss the f-pawn at Black on move two and rip the kingside open. Old-fashioned, yes. Still works.
Scandinavian Defense: Punch at White's centre on move one. Sidesteps most of White's homework.
Fried Liver Attack: Sacrifice a knight to drag Black's king into the open. Then hunt it down.
London System: Same setup every game: bishop out, knights up, pawn wall behind. Boring on purpose; ruthless once Black slips.
Jobava London: London System with the knight thrown at the front. Black's queenside gets harassed before they've finished yawning.
Queen's Gambit: Offer the c-pawn after d4 d5 c4. Black either grabs it (Accepted) or holds the centre (Declined): both paths live here.
Ruy Lopez (Spanish Opening): The oldest pressure play in the book. Pin Black's knight, ask uncomfortable questions, never let them breathe.
Italian Game: Aim a bishop at the most undefended square on Black's board and develop with menace. Their f-pawn does the worrying.
Vienna Game: A knight before a pawn: keeps the f-pawn free for later violence. Black gets a calm opening or a sudden one. Their choice.
Ponziani Opening: An old move that swaps elegance for surprise. Most opponents have no idea what to do and try to remember.
Alapin Sicilian: Refuse the Sicilian's complications. Build a broad centre and let Black explain why they wanted a fight.
Bishop's Opening: Skip the knight and lead with the bishop. Quietly sets up the Italian without committing to the same paths.
English Opening: Push the c-pawn and let Black guess what kind of game you want. Hard to prepare against, easy to enjoy.
Sicilian Defense: Refuse the symmetrical handshake. Imbalanced positions reward the player who knows them better, and that'll be you.
Caro-Kann Defense: Build a rock-solid pawn wall and dare White to find a plan. Quiet equality is its own kind of weapon.
Rousseau Gambit: Sling the f-pawn at the bishop on move three. Wild from the start: White either grabs it or panics.
King's Indian Defense: Give up the centre and build a kingside avalanche. Patient setup, then everything explodes at once.
French Defense: Concede a little space and play for the queenside counter. Cramped early, lethal later.
Petrov Defense: Copy White's knight move and dare them to do something with it. Drainingly symmetrical for anyone hoping for a quick attack.
Albin Countergambit: Sling a pawn at the Queen's Gambit and set the famous knight trap. White either knows the line, or doesn't.
Counter the Vienna Gambit: Black's antidote to White's f-pawn lunge. Punch back in the centre before White has a chance to enjoy themselves.
Latvian Gambit: 38 vetted master lines of the Latvian Gambit. Learn the ideas, add the tool to your bag.

Danish Gambit: Hand Black a pawn or two, on purpose. Both bishops swing onto long diagonals, aimed at the king.

Englund Gambit: Throw a pawn at White's queen-pawn opening and lay a queen-check trap. Natural-looking replies walk right in.

Vienna Gambit: Sacrifice the f-pawn to blast Black's kingside open. A sharper cousin of the Danish.

Traxler Counterattack: Sacrifice the bishop and chase the king into the open. Plenty of these lines simply end in mate.

Stafford Gambit: Hand White a pawn and pour your pieces out while they're still sorting themselves out. A minefield made for blitz.

Scotch Game: Skip the slow Italian and crack the centre open with the d-pawn. Sharp, tactical, your kind of game.

King's Gambit: Toss the f-pawn at Black on move two and rip the kingside open. Old-fashioned, yes. Still works.

Scandinavian Defense: Punch at White's centre on move one. Sidesteps most of White's homework.

Fried Liver Attack: Sacrifice a knight to drag Black's king into the open. Then hunt it down.

London System: Same setup every game: bishop out, knights up, pawn wall behind. Boring on purpose; ruthless once Black slips.

Jobava London: London System with the knight thrown at the front. Black's queenside gets harassed before they've finished yawning.

Queen's Gambit: Offer the c-pawn after d4 d5 c4. Black either grabs it (Accepted) or holds the centre (Declined): both paths live here.

Ruy Lopez (Spanish Opening): The oldest pressure play in the book. Pin Black's knight, ask uncomfortable questions, never let them breathe.

Italian Game: Aim a bishop at the most undefended square on Black's board and develop with menace. Their f-pawn does the worrying.

Vienna Game: A knight before a pawn: keeps the f-pawn free for later violence. Black gets a calm opening or a sudden one. Their choice.

Ponziani Opening: An old move that swaps elegance for surprise. Most opponents have no idea what to do and try to remember.

Alapin Sicilian: Refuse the Sicilian's complications. Build a broad centre and let Black explain why they wanted a fight.

Bishop's Opening: Skip the knight and lead with the bishop. Quietly sets up the Italian without committing to the same paths.

English Opening: Push the c-pawn and let Black guess what kind of game you want. Hard to prepare against, easy to enjoy.

Sicilian Defense: Refuse the symmetrical handshake. Imbalanced positions reward the player who knows them better, and that'll be you.

Caro-Kann Defense: Build a rock-solid pawn wall and dare White to find a plan. Quiet equality is its own kind of weapon.

Rousseau Gambit: Sling the f-pawn at the bishop on move three. Wild from the start: White either grabs it or panics.

King's Indian Defense: Give up the centre and build a kingside avalanche. Patient setup, then everything explodes at once.

French Defense: Concede a little space and play for the queenside counter. Cramped early, lethal later.

Petrov Defense: Copy White's knight move and dare them to do something with it. Drainingly symmetrical for anyone hoping for a quick attack.

Albin Countergambit: Sling a pawn at the Queen's Gambit and set the famous knight trap. White either knows the line, or doesn't.

Counter the Vienna Gambit: Black's antidote to White's f-pawn lunge. Punch back in the centre before White has a chance to enjoy themselves.

Latvian Gambit: 38 vetted master lines of the Latvian Gambit. Learn the ideas, add the tool to your bag.