The Alapin Variation or c3 Sicilian is used by players who want to avoid the Sicilian main lines. When you play against a player who most likely knows the Sicilian Defense very well and has more theoretical knowledge about this opening than you then you could switch to the Alapin variation to escape his well prepared opening lines.1. e4 c5
Alapin Variation - Amateur Chess Opening for White
White wants to set up a classical pawn centre with 3.d4, Black should counter immediately in the centre by 2...Nf6 or 2...d5.
First Main line is 2...d5 3.exd5 Qxd5 4.d4 Nf6 5.Nf3, now Black can choose 5...e6 or 5...Bg4. Usually White gets an isolated pawn on d4.
Second main line is 2...Nf6 3.e5 Nd5 4.d4 cxd4 5.Nf3, when Black has a choice between 5...e6 and 5...Nc6.