King's Gambit Accepted: King's Knight's Gambit is a chess opening with the ECO code C39, part of the King's Gambit Accepted family. It goes 1. e4 e5 2. f4 exf4 3. Nf3 g5 4. h4. White opens with 1. e4 (the king's pawn) and Black answers 1... e5. After 7 moves it is Black to move. After the last move Black is a pawn ahead in material. The lesson on the board explains every move of the line and lets you play it yourself; it is free.
In chessGM's opening book this position continues with 4... g4.
After 1.e4 e5 2.f4, Black takes the pawn with 2...exf4. The game turns wild: White wants a big centre and an attack on f7.
chessGM has a full course for this line: open the King's Gambit Accepted: King's Knight's Gambit course lesson.