Portuguese Opening

The Portuguese Opening is a chess opening that begins with the moves

1.e4 e5

2.Bb5

The Portuguese is an uncommon opening. In contrast to the Ruy Lopez (1.e4 e5 2.Nf3 Nc6 3.Bb5), by delaying Nf3 White leaves the f-pawn free to move and retains the possibility of playing f4. The trade-off is that White's lack of pressure on e5 leaves Black with a freer hand.

If Black replies 2...Nf6, White can try a gambit with 3.d4. Another Black reply is 2...Nc6, possibly hoping White will transpose into the Ruy Lopez with 3.Nf3, but a more popular try is to kick White's bishop with 2...c6. The game might continue 3.Ba4 Nf6 and now White can play 4.Nc3 or 4.Qe2.

Graham Burgess remarks that it looks like a Ruy Lopez where White has forgotten to play 2. Nf3. However there is more to it than that, it is one of those openings that is not as bad or nonsensical as it first appears and Black should proceed carefully.