Intermediate: Openings to Counter/Avoid the London System?

One of my friends always plays the London System - and to add to that, many of my classmates play the London too. Although I don't have any specific trouble with the London, I want to mix things up, and not get the same position every single game.

1 d4 c5. 1 nf3 c5. doesn't fully equalize if you get the czech benoni but it gives plenty of chances to outplay the opponent. like the black side of the closed ruy lopez, particularly when white advances d5 there.

however, 1 d4 c5 2 c3 is lame and you just have to accept that white doesn't want to bother playing interesting chess. if he does, then you get a game, but not very likely. i used to play the london exclusively. i left it as it fostered bad habits. also stunted my creativity. it's not altogether the fault of the opening, but i would say the opening almost ushers you to these kinds of problems later on if you keep playing it to the exclusion of everything else.

The above person gave you an option to avoid the London altogether.

However, when you do decide to enter the London, there is one setup which scores significantly better at what I assume is your level, compared to the other options. And by significant, I mean that Black's percentages go from about 45% to a staggering 60%.

This option is playing 3..c5, followed by 4..Nc6 and 5..Qb6. Here you can see the most common lines in which this arises. If this fits your taste, you can discover more on this opening yourself:

A remark on this setup is that it can be seen as a reversed Queen's Gambit, where this time White is not advised to take the pawn.

There are more lines where 3..c5 (or even 2..c5, sometimes) works, but these two are the most common sights which you can always enter with this setup:

With either a knight on f3 in the first variation, or Bd3/Nd2. You don't really need to learn any of the other variations because White will play into this virtually all the time, and if they don't, that's also an answer to the question you asked: you countered it, since they're playing an inferior setup of the London (or don't play a London at all).

Whether you play 1..Nf6 or 1..d5 depends on what you fear more when the London doesn't get played, but this setup seems to do miracles at your level.

Here's a game where black totally destroys his London System opponent.  It's a nice counter to learn for black:

What to do if white takes the c5 pawn? 

#5
White can take pawn c5, just like black can accept a queen's gambit. Here is an example: