 The Catalan Opening is characterized by White forming a pawn center at d4 and c4 and fianchettoing his king's bishop.It resembles a combination of the Queen's Gambit and Réti Opening.Since the Catalan can be reached from many different move orders, (one Queen's Gambit Declined-like move sequence is 1.d4 d5 2.c4 e6 3.Nf3 Nf6 4.g3), it is sometimes called the Catalan System.