Three Knights Opening is a chess opening with the ECO code C46. It goes 1. e4 e5 2. Nf3 Nc6 3. Nc3. White opens with 1. e4 (the king's pawn) and Black answers 1... e5. After 5 moves it is Black to move. The lesson on the board explains every move of the line and lets you play it yourself; it is free.
The moves
1. e4 – White plays the pawn to e4
1... e5 – Black plays the pawn to e5
2. Nf3 – White plays the knight to f3
2... Nc6 – Black plays the knight to c6
3. Nc3 – White plays the knight to c3
In chessGM's opening book this position continues with 3... Nf6.
About the Three Knights Opening
After 1.e4 e5 2.Nf3 Nc6 3.Nc3, Black plays something other than ...Nf6. White develops simply and keeps options.
Black may play ...Bb4, ...Bc5 or ...g6 instead of the fourth knight.
White can answer with d4 to open the centre.
It often transposes to the Four Knights or Scotch.