Paulsen Attack

The Paulsen Attack, also called the Paulsen Variation, is White's answer to 3...d6 in the Classical Variation in which the attacked knight goes to c4 rather than back to f3. The retreat leaves the d-pawn unobstructed, which is its advantage over 4. Nd3, the Karklins–Martinovsky Variation, but the knight has no secure post on c4 and typically relocates to e3 later. White is momentarily a pawn ahead, yet nothing prevents Black from collecting the e4-pawn at once.

The great majority of games continue 4...Nxe4, restoring material balance with a knight centralized on e4. Developing alternatives such as 4...Nc6 and 4...Be6 occur only occasionally, and the engine also ranks 4...Qe7 among Black's best moves. Engines assess the position as level, so the line offers White little of the edge the main 4. Nf3 lines aim for. In Modern Chess Openings Nick de Firmian dismissed it as ineffective, although it still turns up from time to time among grandmasters. In online play it is uncommon, and Black scores slightly better than White.