French Defence - when not to play

Black has already chosen to play the French defence by playing 1e6 in reply to 1e4. So, you will need to expand on your question by saying what bothers you about White's reply to it.

Well, not totally!  There are transpositional possibilities.

Typically, after 1.e4 e6, against most of White's responses, Black should follow up with 2...d5, whether that be after 2.d4, 2.f4, 2.Nc3, 2.Nf3, 2.b3, etc.

2.d4 d5 is the Straight up French Defense

2.f4 d5 is simply an odd line by White that isn't very good.  He will usually advance e5, but then has the wrong pawn covering e5, and blocks in his Bishop.  It also gives Black the opportunity to advance ...d4 at some point and open up his bad bishop.

2.Nc3 d5 will usually lead to the Two Knights variation after 2.Nf3 or transpose back to the normal French with 3.d4.

2.Nf3 d5 will usually lead to the Two Knights variation or the Wing Gambit (3.e5 c5 4.b4).  Some ignornant chess players that don't understand the concept of taking the center when given to them and play 2.Nf3 like a robot might exchange with 3.exd5 exd5 and then play 4.d4, which directly transposes to the 4.Nf3 Exchange Variation, and the early Nf3 is inferior to other exchange lines for White.

2.b3 usually leads to a little known Gambit after 3.Bb2 dxe4 4.Nc3 Nf6 5.g4.

There is one line, however, where playing 2...d5 is NOT a good idea, and that is after Chigorin's intervention, 2.Qe2.  Here you should play 2...c5.  If White directly transposes to the KIA, you can transpose to the KIA vs French, but make sure you play ...Be7 before you play ...d5, like 1.e4 e6 2.Qe2 c5 3.Nf3 Nc6 4.g3 Be7 5.Bg2 Nf6 6.d3 d5 7.O-O O-O, just as one example of a possible move order.  Both sides can of course deviate and so you can't force the line.

However, outside of 2.Qe2, or something really stupid that just hangs material, like 2.Ba6, I would say 2...d5 is your best move.  But be ready to play certain "KIA vs Sicilian" type lines against 2.Qe2.

Even 2. Qe2 d5 is not much worse for black because after Qxd5 Nc3 Qd8 how does white play d4

I think that when playing the french defense as black, all you need to worry about is 2. d4, because that is what most players will go for, but however you should try to know all of whites possibilities on the 2nd move so you are prepared, like any opening really.

like this :

Anyway : black is not forced to take the pawn, and white has other options than playing d4 so soon. For instance :