Valencian Variation (3...Qd8)

Scandinavian Defense

1.e4 d5 2.exd5 Qxd5 3.Nc3 Qd8 4.d4 Nf6 5.Nf3 Bg4

The queen goes all the way back to d8, and the bishop comes out to g4.

The idea

After 3...Qd8 4.d4 Nf6 5.Nf3 Bg4, Black's queen is safe at home, and the bishop pins the knight on f3. Black has spent two queen moves to end where it started, but the position is solid. Lichess calls this the Valencian Variation's main line.

Plans for White

Use the extra time. Develop with Be2 or Bc4 and h3 to put the question to the bishop, castle and use the space White's d4 pawn gives. Wikipedia calls the line somewhat passive for Black, and White should aim to keep the initiative.

Plans for Black

Develop with ...e6, ...Be7 or ...Bd6, ...c6 and ...Nbd7, then castle. If White plays h3, Black decides between keeping the pin with ...Bh5 and trading on f3 to ease the position.

Watch out for

For Black, falling too far behind. 3...Qd8 was once the main line, but Bobby Fischer's quick win against Karl Robatsch in 1962 put the setup with ...g6 under a cloud, as Wikipedia puts it.

For White, the pin. Until White breaks it with h3 or Be2, the knight on f3 can't leave without losing the queen, and ...Bxf3 can damage White's pawns.