Editing Petrov's Defence (section)

====Other replies====
3...Nxe4, the Damiano Variation, has traditionally been regarded as an error, though it has occasionally been seen in recent grandmaster play. Black must play accurately to avoid a serious disadvantage. After 4.Qe2 Black must avoid:
* 4...Nf6{{chesspunc|??}} 5.Nc6+ winning the queen
* 4...d5{{chesspunc|?}} 5.d3 Qe7 6.dxe4 Qxe5 7.exd5 and Black loses a pawn
* 4...d6? 5.Nxf7{{chesspunc|!}} Kxf7 6.Qxe4 and Black has lost a pawn and the ability to castle

Best is 4...Qe7 5.Qxe4 d6 6.d4 dxe5 7.dxe5 Nc6, and after 8.Nc3 Qxe5 9.Qxe5+ Nxe5 10.Nb5 (or 10.Bf4) White has the advantage.<ref>Janjgava, pp. 108–09</ref><ref>Yusupov, pp. 12, 22–24</ref> 

3...Qe7{{chesspunc|?!}} is inferior, as 4.d4 d6 5.Nf3 Qxe4+ 6.Be2 gives White a large lead in development.

<span class="anchor" id="Stafford Gambit"></span>
3... Nc6?!, recently dubbed the Stafford Gambit, is considered dubious, but it sets a number of [[List of chess traps|traps]], and in the early 2020s it became popular in online blitz and bullet games. After 4.Nxc6 dxc6, White wins a pawn but must play carefully. After 5.e5 (5.d3 is better) Ne4 6.d3?? (White should play 6.Nc3, 6.d4, or 6.Qe2) 6...Bc5! and White resigned in Lowens–Stafford, US correspondence game 1950.<ref>{{cite web |url=https://www.chessgames.com/perl/chessgame?gid=1243149 |title=Lowens vs. Stafford, 1950 |website=[[Chessgames.com]] }}</ref><ref>Forintos & Haag, p. 110</ref> After 1.e4 e5 2.Nf3 Nf6 3.Nxe5 Nc6 4.Nxc6 dxc6 5.d3 Bc5, White must avoid the [[Légal Trap]] 6.Bg5?? Nxe4!, and if 7.Bxd8 (relatively best but still losing is 7.Be3) 7...Bxf2+ 8. Ke2 Bg4#. Instead White should play 6.Be2 Bc5 7.c3! with d3-d4 to follow, and Black has insufficient compensation for the pawn, though White must still play carefully.<ref>[[Avetik Grigoryan]], [https://chessmood.com/blog/stafford-gambit-the-refutation Stafford Gambit ― The Refutation], Chessmood, 6 April, 2021</ref>