what do you do in htis case?

hi all, just wondering what peoples general strategy is for the following:

You have your favourite openings and look to play them. Let's say you are black and you enjoy the Karo-Cann. So white opens with 1.e4, perfect, lets hope we can play the CK here. If white knows the theory and co-operates, as black, you could easily be 10 moves in and very comfortable. But what if white doesn't know theory, has perhaps never even heard of the CK and after 1.e4 proceeds to play what appear to be random moves. Now 10 moves in, you might still be comfortable as black, or, as I often find, I am no very uncomfortable and struggling.

So my question is: what is your general strategy for situations where white (or black) dont play theory and make aggressive, 'random' moves, do you still try to push your opening set up and ideas, or do you abandon them quickly and just play sound chess ?

Thanks

I try to follow as closely as possible my opening repertoire. This gets me to middle game positions which I'm familiar.

IMO, trying to avoid any pitfalls of a prepared player is almost hopeless, but for a truly random player, it's still better to play soundly and take advantage of his play when you get the advantage.

Understand why the theory is theory, if that makes sense. GMs play those moves for a reason, not because they're fashionable. While there are always novelties to be found, if you understand what threat your opponent is countering with a move, you can better exploit it when they stray from established theory into something else. Sometimes it is more of a fashion/style thing, but there's always a reason why theory is theory, if that makes sense. To untangle that, make sure you know why the theory is as it is. And honestly, some peeps just like to get you out of book - finding out why that's suboptimal OTB is hard though, so yes, play sound chess at that point :)

neither. i just play chess960, the superior form of "chess".

To be fair, as i see it you don't need to know "10 lines moves of theory" to play chess well, apart from at the professional level. You can just make a broad analysis and analyse 15 different variations and then beat everyone tho

If you know 10 lines of theory, you should also know for each of them what their purpose is. As @SomewhatUnsound said: They are theory for a reason. If your opponent does something that grants you some advantages "for free" (e.g. lets you control the center for which aim you learned a couple of theory lines because usually the opponent won't be so generous) - then you can look for other targets. Maybe your theory lines are a waste of time after some unorthodox moves of your opponent.

If you really understand theory, you should know why White should play certain moves in the next move. When learning, dont just learn the moves, learn what they do.