Sodium Attack: Durkin Gambit is a chess opening with the ECO code A00, part of the Sodium Attack family. It goes 1. Na3 e5 2. Nc4 Nc6 3. e4 f5. White opens with 1. Na3 and Black answers 1... e5. After 6 moves it is White to move. The lesson on the board explains every move of the line and lets you play it yourself; it is free.