411 REFERENCE · Wikibooks
Chess Opening Theory/1. e4/1...e5/2. Nf3/2...Nf6/3. Nc3
Reference material by Wikibooks contributors. This retains its source identity and is not 411 news reporting.
Three knights variation Russian game C42
3. Nc3 · Three knights variation
Black's most common response to this move is 3...Nc6, which transposes into the Four knights game.
Black can also play 3...Bb4.
Theory table
1. e4 e5 2. Nf3 Nf6 3.Nc3
3
Four Knights
...Nc6
Bb5
(to 2...Nc6 3.Nc3 Nf6)
Petrov Defense
...Bb4
Nxe5
References
Petrov's Defence