When to play on the queenside (in same side castling scenarios)

Can someone articulate in simple terms in what situations (especially with a FEN/PGN) you believe the correct plan would dictate queenside play? I think it'd be great to hear a range of different explanations from people at the different rating levels, and we can all compare and contrast our perspectives from each other.

Many people understand when to attack on the kingside or play in the centre. An area that seems to be particularly ambiguous for many is what heuristics to look out for, when, and what the point of a queenside play might even be, when there is neither king is on the queenside.
Minority attack is an example that comes to mind, but that's not necessarily to do with it being on the queenside. What are some typical stock plans and motifs to look out for, that dictate queenside play would be optimal? A collection of these would be great study material for all.

"in what situations (especially with a FEN/PGN) you believe the correct plan would dictate queenside play? " ++ When the pawn configuration dictates so. Here is a PGN: 9 b4!
https://www.chessgames.com/perl/chessgame?gid=1070932

"what the point of a queenside play might even be"
++ To weaken and then win a pawn and then queen it.

Because it will make for an interesting discussion. I appreciate his effort.

I think the majority of KID variations fit this idea.

#3. Of course, as a chess coach, I ask many simple questions of chess players. I like to understand peoples general ideas from various different skill levels.

I was inspired by a YouTube video of another great coach who was speaking about space and what people perceive space to mean and in particular, a space advantage, and then what to do about it.
Many people have an idea of what space is, a space advantage not so much, and what to do about it specifically, it often then breaks down.

There’s then the popular videos on YouTube of experts explaining subjects at various different levels of complexity with students of varying degrees of understanding, like 5 levels of Gravity, etc I learn quite a lot from videos like that, especially when the initial explanation starts out very simple, then gradually gets deeper from there.

I think similar formats, covering different concepts on here would help the masses! Helps me at least!

#5, correct, there’s queenside play in KID. I’d be interested in why / what the purpose of that is? When is it the thing to do vs when is it not the thing to do? What heuristics are you looking for?

I think the simple answer is, because the pawn structure demands it. but the purpose is different for white and black.

your original post confined the scenario to both sides being castled king side and play being on the queenside. did you mean only for white? in terms of the KID, most all of blacks play is on the king side except for the Averbahk and the Saemich variation.

Usually to throw a pawn attack at the opponent's king, whilst keeping my king shielded by other pawns. If I have enough initiative in attack and space to launch pawns into.

Otherwise in some variations of some openings, there is a specific tactical advantage, like a discovered rook attack on the opponent's queen down the d-file.

I'm enjoying the nature of the question and discussion!

Yes. A more specific (though not foolproof) formulation is that, when there are pawn chains, you typically play on the side of the board that your pawn chain is pointing to. That's why, in the King's Indian, White often plays on the queenside and Black plays on the kingside. Winning on the queenside may not lead to checkmate, but if, as White, you don't get checkmated yourself and win some pawns on the far side of the board, that often means you win the endgame. For one thing, having won on the far side of the board means both kings kings are far away from White's the advancing pawns, unlike with Black's advancing pawns, which are easier to stop.

Here's an example game of the sort: https://www.chessgames.com/perl/chessgame?gid=1596153

There are exceptions, though -- the Ruy Lopez, for instance, often has a closed center with pawn chains that look like KID pawn chains, but there Black tends to play on the queenside (especially if they have a semi-open c-file to work with), where White tends to attack on the kingside.

Karpov attacked on the queen side against Polgar.