yes but i am looking for a reply to 1.d4 as black. not for a new opening as white! but thanks for you opinion anyway
Defense to 1.d4

Dutch (1...f5) throws off a lot of d4 players. You can set up in a stonewall formation or play more positionally with a Leningrad formation.
If you're looking for a nice surprise weapon, I recommend the Blumenfeld Counter Gambit. (1. d4 Nf6 2. c4 e6 3. Nf3 c5 4. d5 b5). It takes careful play if white makes the best moves, but most people don't know it.

I don't think you'll find a defense to 1.d4 which leads to similar positions as the Sicilian. If you're looking for a fighting defense to 1.d4 which is also sound then I might also recommend the Dutch or the Nimzo-Indian.
It kind of depends - your typical Sicilian player may not be looking to play a gambit as black against 1.d4. In response to post #4 above, most white players will play 3.Nc3, so I wouldn't spend too much time trying to learn the Blumenfeld. Perhaps instead play the Benko? 1.d4 Nf6 2.c4 c5 3.d5 b5
Against 1. d4 I use King's Indian. It leads black into a pretty nice position, but I wouldn't say it's at all like the scicillian. Here's how I play King's Indian.

@benedictus: after ...c5 d5 exd5 cxd5 there, you've transposed into the Modern Benoni. If you follow the opening categorizers, you're not playing a KID anymore after that :-)

Quite an offbeat opening that I am becoming fond of is the 'Mexican Defence' or 'Black Knights Tango' or (one of many other names) where you start off by bringing out your two knights. It looks a little silly, and indeed, you're somewhat banking that White may think that you're some sort of muppet for doing this. However, if white doesn't sense danger and develops classically with 3. Nc3 then you can respond with 3...e5 and already white can be in a spot of serious bother. The below game gives an example of the attacking capabilities that black has from the opening.
At your level I'd imagine that to be the most common response, and I think it's fair to say that black has more than reasonable counterplay.
Even if white plays the correct third move of Nf3. then you can usually transpose it into a Nizmo-Indian, so either way there are good possibilities for black.

Hi DreamLines, I was wondering what you play after 1. d4 Nf6 2. c4 Nc6 3. Nf3 e6 4. a3 ? The best seems to be to play d6 and g6 and try to go for a king's indian setup with the extra moves a3 and e6, but in this case a3 is probably the more useful extra move.
This line along with 3. Nc3 followed by an early h4 have troubled me the most when I played the black knight's tango as my main defense to d4.

I usually play King's Indian Defense, however...
What do you guys think about 1)...c5?
What does the computer give c5 as a response? plus, minus, equal?

Hi DreamLines, I was wondering what you play after 1. d4 Nf6 2. c4 Nc6 3. Nf3 e6 4. a3 ? The best seems to be to play d6 and g6 and try to go for a king's indian setup with the extra moves a3 and e6, but in this case a3 is probably the more useful extra move.
This line along with 3. Nc3 followed by an early h4 have troubled me the most when I played the black knight's tango as my main defense to d4.
Look at a game from my most recent history against richie_and_oprah, where we go through exactly this line.
The final combination by richie is worth the look also! I totally missed Rxf3+ (well actually I missed Qe2+ if I take the rook).

Against 1. d4 I use King's Indian. It leads black into a pretty nice position, but I wouldn't say it's at all like the scicillian. Here's how I play King's Indian.
What about the nimzo bogo?

I usually play King's Indian Defense, however...
What do you guys think about 1)...c5?
What does the computer give c5 as a response? plus, minus, equal?
That's the Old Benoni. It just transposes into another Benoni line.
Ok, so what do you guys think about the Benoni? Does it work for you? Do you use is? Do you think it's bad for black?
I have never played c5 vs d4 so I am asking for opinions of those that have or do. It's good to learn.
I'm a Sicilian player and I like the Tarrasch Defense (not that it leads to theoretical positions similar to the Sicilian theoretical positions, but at the amateur level, the Sicilian player often reaches positions way different from the theoretical positions, because one player or the other will usually deviate from the book line very early in the game, and reach positions that are more like (although not the same as) the Tarrasch Defense.

I usually play King's Indian Defense, however...
What do you guys think about 1)...c5?
What does the computer give c5 as a response? plus, minus, equal?
That's the Old Benoni. It just transposes into another Benoni line.
Ok, so what do you guys think about the Benoni? Does it work for you? Do you use is? Do you think it's bad for black?
I have never played c5 vs d4 so I am asking for opinions of those that have or do. It's good to learn.
In a recent issue of Chess Life, they quoted Kasparov teaching some kids (very high rated kids) and he answered exactly this question. He said the Benoni is very bad. They asked him what they should play against it, and he said "anything". I think his implication was that at the highest level it is no longer considered really a usable weapon for black.
Personally I never play it as white or black, and I haven't followed the theoretical debate in it over the past 20+ years, so I can't really expand on that.
My opinion on 1.d4 c5 as a defense - probably Kasparov would just say 1.d4 c5 2.d5 and white is better! LOL! But for us mortals, it seems to me that white may be able to make use of the fact that he hasn't played 2.c4 to his advantage - in other words perhaps white can get Nd2-Nc4 in which sometimes is a great square for the knight. Other than that, there's the 1.d4 c5 2.d5 e5 line. I'm just not that familiar with what black is trying to achieve in these lines, sorry. :-(
I need help playing against d4. Normally, against e4, i use the sicilian defense and when playing white, i try to play the ruy lopez. Are there any defenses to d4 which would lead to similar positions or play like the sicilian or ruy lopez?