Réti Opening, Réti Accepted

The Réti Accepted appears after White develops the knight to f3, Black plays ...d5, White challenges that pawn with c4, and Black captures on c4. In opening terminology, accepted means Black takes the offered pawn; it does not mean White gives up trying to recover it.

Black's pawn on c4 gives Black extra material, meaning one additional pawn, but it is separated from Black's center and may be difficult to defend. White often uses the time to develop and recovers it later. e3 opens the f1-bishop's diagonal toward c4; Na3 develops a knight with the idea of reaching c4; Qa4+ gives check and attacks the pawn along the fourth rank.

Black may try to support the pawn with ...a6 and ...b5, but those moves consume time and advance pawns on the queen's side. If the c4-pawn falls anyway, White may finish development comfortably. If White tries to recover it without preparation, however, the queen or another piece may move repeatedly and lose the advantage of having more active pieces.

The capture distinguishes this branch from the Advance Variation, where Black's pawn continues to d4, and the Anglo-Slav, where it stays on d5 supported by ...c6.