The Fajarowicz Variation of the Budapest Gambit, 3...Ne4, gives up a pawn not to win it back but to create immediate tactical threats. This trap is its signature miniature, recorded in the opening's literature: White chases the knight with the queen, grabs pawn after pawn, and after Black's quiet 9...Qe7 discovers that the queen has no safe square. The retreat 10.Qd1 looks safest of all, and it is answered by 10...Nd3, checkmate in ten moves.
White attacks the e4 knight with 4.Qc2, and Black develops with 4...Bb4+, 5...d5 and 6...Bf5, gaining time on the queen. While White's queen wanders to a4 and the d6 pawn munches on c7, Black plays 8...Nc5! and 9...Qe7!, pinning the e2 pawn. Every queen move now fails, and 10.Qd1?? allows 10...Nd3#, a Kieninger-style smothered mate.
After 1.d4 Nf6 2.c4 e5 3.dxe5 Ne4 4.Qc2 Bb4+ 5.Nd2 d5 6.exd6 (en passant) Bf5, Black has developed three pieces with threats while White has moved the queen twice and blocked the d2 square with a knight. 7.Qa4+ Nc6 8.a3 tries to win a piece by hitting the b4 bishop, but 8...Nc5! turns the tables: the knight attacks the queen, and 9.axb4 Nxa4 10.Rxa4 would give up queen for bishop and knight. White grabs another pawn with 9.dxc7, hitting the d8 queen, and Black calmly plays 9...Qe7!. That move does two jobs: it steps off the c7 pawn's attack and it pins the e2 pawn against the king on the open e-file. Now the white queen, attacked by the c5 knight, has nowhere good: 10.Qxb4 Nxb4, 10.Qc2 Bxc2 and 10.Qb3 Nxb3 all lose her outright. The game move 10.Qd1?? looks like the one safe retreat, and it blocks the king's last flight square: 10...Nd3# is mate, because the pinned e2 pawn cannot capture, d2 holds White's own knight, f1 the bishop, and f2 is covered by the knight itself.
10. Qd1 — 10.Qd1?? (ply 19) is the losing move: the queen retreats to the one square that seals the king's fate, and 10...Nd3# ends the game. By that point the damage was done; after 9...Qe7 every queen move lost material, and d1 merely lost the most. The real cause is earlier: three pawn-and-piece grabs with the queen while Black developed with tempo on every move.
As White against the Fajarowicz, do not make the queen your first developed piece. The knight on e4 is annoying, but calm development (Nf3 and e3, or a timely Nd2 to challenge it) keeps the extra pawn without adventures. If you find yourself checking on a4 and pawn-grabbing on c7 by move nine, you have already gone wrong. And whenever your queen is attacked, count every escape square before trusting the obvious one: here the safest-looking retreat was the only one that got mated.
Because it is pinned. Black's ninth move, ...Qe7, put the queen on the open e-file, staring straight at the king on e1. If the e2 pawn captures on d3, the king is in check from the queen, so the capture is illegal, and that is precisely why 10...Nd3 is mate rather than a blunder.
It is a surprise weapon rather than a main-line defense: White keeps an edge with sober development, which is why you rarely see 3...Ne4 at master level. But the tactics are absolutely real. The same ...Nd3 smothered mate pattern appears in the Budapest's Kieninger Trap, and a queen-happy White can lose in ten moves, as here.
A trap only works if your opponent makes the mistake — strong players sidestep these, which is why each page also shows how to avoid it. Every line here is checked legal with the same engine the board runs, and every checkmate is verified.