Semi-open games

Modern Defense

1.e4 g6

The Modern Defense starts with 1.e4 g6 and is catalogued under ECO B06, in the semi-open games half of the book. The catalog indexes 39 lines inside it, grouped into 37 named variations, and the position after those moves has 8 playable continuations to walk from here.

Opening repertoire map

Root edges show how often each move is played around your Elo. Use the arrow on a position to reveal the next replies.

Current position
Modern Defense
Popularity by Elo
Share of Lichess blitz, rapid, and classical games that continued with each move.
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Current setup

Move ideas

  1. 1.e4

    Claims the center with a pawn and opens lines for the queen and king’s bishop.

    Idea: Build quick development and make early castling possible.

  2. 1…g6

    Advances the g-pawn to gain kingside space and control new squares.

    Idea: Create useful wing space while keeping the central structure flexible.

  3. 2.d4

    Advances to d4 to claim central space and control nearby key squares.

    Idea: Give the pieces room to develop behind a durable central foothold.

  4. 2…Bg7

    Develops the bishop to g7, bringing it into the game.

    Idea: Improve piece coordination and clear the back rank for castling and the rooks.

Book continuations

Waiting for Lichess game popularity.

8 moves
Nc3Modern Defense: Standard Line17 named lines · Modern Defense: Anti-Modern · Modern Defense: Standard DefenseDevelops the knight to c3, bringing it into the game.Idea: Improve piece coordination and clear the back rank for castling and the rooks.c4Modern Defense5 named lines · Modern Defense: Dunworthy Variation · Pterodactyl Defense: Central, AnhangueraAdvances the c-pawn to gain queenside space and control new squares.Idea: Create useful wing space while keeping the central structure flexible.f4Modern Defense: Three Pawns Attack3 named lines · Pterodactyl Defense: Austrian, Pteranodon · Pterodactyl Defense: Austrian, Austriadactylus WesternAdvances the f-pawn to gain kingside space and control new squares.Idea: Create useful wing space while keeping the central structure flexible.Nf3Modern Defense3 named lines · Modern Defense: Geller's System · Pterodactyl Defense: Western, AnhangueraDevelops the knight to f3, bringing it into the game.Idea: Improve piece coordination and clear the back rank for castling and the rooks.Bc4Modern Defense: Bishop Attack2 named lines · Modern Defense: Bishop Attack, Bücker GambitDevelops the bishop to c4, bringing it into the game.Idea: Improve piece coordination and clear the back rank for castling and the rooks.g3Modern Defense2 named lines · Pterodactyl Defense: Fianchetto, Rhamphorhynchus · Pterodactyl Defense: Fianchetto, King PterodactylAdvances the g-pawn to gain kingside space and control new squares.Idea: Create useful wing space while keeping the central structure flexible.Bd2Modern Defense: Westermann Gambit1 named lineDevelops the bishop to d2, bringing it into the game.Idea: Improve piece coordination and clear the back rank for castling and the rooks.Bd3Modern Defense: Wind Gambit1 named lineDevelops the bishop to d3, bringing it into the game.Idea: Improve piece coordination and clear the back rank for castling and the rooks.

Named variations

Each line below is an indexed entry under Modern Defense. Open one to load it on the board and keep exploring from that position.

13 more named lines sit inside this family — the tree above walks all of them.

Openings from the same volume

ECO groups openings by the structures they lead to, so these families tend to share plans with the Modern Defense.