How useful is it to study more than one opening?

my uneducated option is memorising the moves of openings is different to memoising the reason for the moves.

blitzing out the correct moves without understand what each move does, what the move prevents your opponent from doing, what it allows your opponent to do, what it provides you, what the middle game goal is, etc, won't make you better at chess.

after learning and understanding one opening, the second one should be quicker and easier to understand.

i just memorise the first few moves. I don't know the purpose of them.

Studying different openings is certainly the right approach if you want to gain a broader understanding of chess - and the broader understanding is important if you want to be a really strong player.
There are many players who are only playing one repertoire their whole life - either because they only played online or OTB on a level where preparation was non-existent. But after some years or decades, it is more or less impossible for them to adapt new openings and they will struggle if they play against a prepared opponent.

"... Overall, I would advise most players to stick to a fairly limited range of openings, and not to worry about learning too much by heart. ... the average player only needs to know a limited amount about the openings he plays. Providing he understands the main aims of the opening, a few typical plans and a handful of basic variations, that is enough. ..." - FM Steve Giddins (2008)

Ask Magnus Carlsen ** We never had a world champion with such a wide repertoire and such broad knowledge.

Or ask yourself ** are you satisfied with an extremely limited understanding of the game, which may be effective in the short run? or do you want to learn all there is to learn, for the pleasure of it?

listen to @Nougatchoc

@sparowe14 said in #24:

Ask Magnus Carlsen ** We never had a world champion with such a wide repertoire and such broad knowledge.

Or ask yourself ** are you satisfied with an extremely limited understanding of the game, which may be effective in the short run? or do you want to learn all there is to learn, for the pleasure of it?

listen to @Nougatchoc

Carlsen's repertoire is a mile wide and an inch thick. Nothing to fear. Fischer had the most narrow repertoire of all time in some ways.

Fischer said to read MCO from cover to cover twice as a prospective student's first lesson.

In 1984 I bought MCO and "sampled" every opening in the book. It's useful, but over time I developed a much more narrow repertoire, though I've changed it so many times I now have like six repertoires.

My belief that "you don't know anything until you know everything" says to study anything and everything.

MCO is dreary, deadly dull. Mere mortals cannot learn that much.
Magnus seems to only want to learn enough of an opening to get to a playable position, after which he figures things out as he plays. He doesn't do the heavy prep stuff.

@sparowe14 said in #27:

He doesn't do the heavy prep stuff.

According to Fabiano Caruana, Magnus is the "best prepared player to ever live".

The second MCO-reading was what Fischer referred to as being for the second lesson. Anyway, in Discovering Chess Openings, GM John Emms expressed the view that Fischer was being "tongue-in-cheek, I'm sure". Opening encyclopedias (in book form) seem to have become a much less important part of chess literature. The last time I saw a new MCO (#15) was about 14 years ago.

There was a guy, now a GM, can't remember who, but his coach only taught him opening theory after he became an IM. Before that they just trained on middle game and endgame. Learning opening isn't that important early on. You just need to know to play for the centre, get king to safety and watch out for pawn pins. As long as you can develop your pieces and get them to good squares, before you become a titled player, don't really study openings. A few you should know is Ruy Lopez (quite common), Sicilian and Queen's Gambit, and English, to name a few