3 Check Opening Ideas For Black In the French Sicilian: Part 3 (5. Bb5)

Plans and ideas:

• Play a6 to force the exchange on c6. This will prevent any Nxd5 ideas from White.
• If given the chance play d5-d4 to gain space and to open your light squared Bishop. Piece activity is much more important than material so sometimes you can even do this as a pawn sacrifice.  
• If White does not allow d5-d4 then try to exchange your light squared Bishop for any White piece if possible, usually via b5. However, don't try to trade this Bishop too early as White might be able to launch a quick attack if your King is still multiple moves away from castling to safety.
• If you castle Kingside then you can try to gain play on the f-file with either f6 or f5.
• Another idea after castling Kingside is to open the c-file and then infiltrate on the Queenside.
• Sometimes you can leave your King in the center and start a pawn storm with your Kingside pawns.

Where to put your pieces?

• The Queenside Knight goes to c6 and will likely be traded for White's light squared Bishop.
• The light squared Bishop goes to d7 to recapture on c6.
• The Kingside Knight goes to f5 via e7. g6 is an alternative square for this piece.
• The dark squared Bishop goes to e7 or c5 if White decides to exchange pawns there.
• The King usually castles Kingside but you can also consider leaving your King in the center in some cases. Castling Queenside is risky in this line since the pawn on a6 is a target for White to attack.
• If you castle Kingside then you can lift your Rook(s) on the f-file after you've advanced your f-pawn to start an attack on the Kingside. If a Kingside attack doesn't look promising then double your Rooks on the c-file instead and look for opportunities to invade on White's 2nd or 1st rank.
• The Queen can maneuver to the Kingside or the Queenside depending on where the action is.