Chess Openings Lab
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French Defense: Marshall Gambit

The Marshall Gambit is 3...c5 in the French, opening the center before Black has developed a piece. White wins material or a lasting edge with 4.exd5 and a check on b5, while Black hopes for active play with an isolated d-pawn.

Moves
1.e4 e6 2.d4 d5 3.Nc3 c5
ECO
C10
Engine
+1.27 · a clear edge for White (Stockfish 17.1, depth 20)
Played
2,819 games in our lichess sample
White scores
54.2%

Key ideas for both sides

White

  • Take on d5 with 4.exd5, then check on b5 after ...exd5. The engine line wins the c5 pawn with dxc5.
  • Answer ...d4 by checking on e2 with the queen, keeping Black's king in the center.
  • 4.Bb5+ also works: after ...Bd7 and the trade on b5, the b5 knight is very active.
  • Develop fast with Nf3 and Be3 and target the isolated d5 pawn.

Black

  • After 4.exd5 recapture ...exd5 and block the check on b5 with ...Nc6.
  • Push ...d4 to hit the c3 knight and gain time, as the top engine line shows.
  • Develop ...Nf6 and ...Be7 quickly and castle; Black's king is the main target.
  • Use the isolated d-pawn for piece activity: ...Nc6, ...Bd6 and pressure on the e-file.

Plans and pawn structure

Black has opened the center a few moves too early. After 4.exd5 exd5 5.Bb5+ Nc6 6.dxc5, White is a pawn up and Black's d-pawn is weak, so White develops with Nf3, Be3 and short castling and blockades the d-pawn. Black needs quick development and checks on the e-file to make the extra pawn hard to use. If Black survives the opening, the game is an isolated pawn fight where White has the better side.

Where the engine's main line heads: White has doubled c-pawns. White's c-pawns are doubled, usually after ...Bxc3 bxc3. In return White keeps the bishop pair and a solid center.

What the engine plays from here

Stockfish 17.1 at depth 20 rates the position +1.27: a clear edge for White. Its three top choices for White:

  1. +1.27 4.exd5 exd5 5.Bb5+ Nc6 6.dxc5 d4
  2. +1.17 4.Bb5+ Bd7 5.exd5 Bxb5 6.Nxb5 a6
  3. +0.49 4.Nf3 cxd4 5.Bg5 Nf6 6.Nxd4 Be7

Pawns, from White's side.

How it scores on lichess

2,819 rated lichess games reached this position; White scored 54.2%.

under 120054.5%
1200–159953.8%
1600–199953.7%
2000 and up57.8%

Light: White wins. Grey: draws. Dark: Black wins. About the sample.

How to play against it

As White, play 4.exd5 exd5 5.Bb5+ and follow the engine line: take on c5, check on e2 when Black pushes ...d4, then develop and castle. Do not grab more pawns while your king is in the center. As Black, prefer ...Nf6 or ...dxe4 on move three, which keep a normal French.

Questions

What are the moves of the French Defense: Marshall Gambit?

The French Defense: Marshall Gambit starts 1.e4 e6 2.d4 d5 3.Nc3 c5. Its ECO code is C10.

Is the French Defense: Marshall Gambit good for Black?

Stockfish 17.1 rates the position +1.27 at depth 20, which is a clear edge for White. In 2,819 lichess games from our sample, White scored 54.2%. A dubious choice for Black; White players who know 4.exd5 and 5.Bb5+ get a clear advantage, so Black needs a strong taste for risk.

What is the main idea of the French Defense: Marshall Gambit?

Black plays ...c5 before developing, hoping for quick activity. White opens the center with 4.exd5 and a check on b5 and wins material or gets a lasting edge.

What should White play next?

The engine's first choice is exd5, with Bb5+ and Nf3 close behind. 4.exd5 opens the e-file and prepares a check on b5 that leaves Black's center and king exposed.

Updated October 2026. Sources and method.