user1549: I'm a hobbyist chess player and usually play online. While I've seen thousands of great chess games and win a fair number of games online, the one thing that I have struggle with is studying openings. Simply put, there are just so many of them and each of them has so many variations. And to add to that, every out-of-book move my opponent makes throws me off and I don't know how to continue, so it turns out to be some hybrid/weird opening (or perhaps its a real opening with a name that I just don't know about)
I guess my question would be:

What's a good way to learn some of the common/easy openings? Is it
just memorize or understanding the principles for instance, what
that particular opening is looking to achieve?
How do I identify which of the variations to look at for a
particular opening, there are often so many?
What's a good strategy to deal with my opponent suddenly going out
of book or playing a novelty in an opening that I've memorized?


user12402: Write the various ideas that you discover in the opening. For example, in the Taimanov Sicilian against the English Attack when White attacks the Knight with g5, Black should consider playing  Nh5 and using the Knight to blockade the kingside. As you understand more and more ideas in the opening (and write them know), you'll begin to understand that it's not about memorizing moves but understanding how to respond to various plans that the opposing player can try.  That's should be your mindset when learning an opening.  Don't memorize - understand.

user3872: The best way, in my opinion, to learn opening theory is to study a chess database. Chessbase has a free one online, and so does chesstempo.
Look up games that match a particular position of your choosing. See what moves strong players play (also look at win percentages). Think about what moves you or an opponent would play in a particular position, and see how strong players respond. If there are no, or only a few games played in whatever line you are investigating, you can use a free engine, like Stockfish for example. Lastly, every time you play a game of chess, think about looking up in the database the opening that you played.  And of course, the entire time, you must try to understand why the moves are being played. If you don't do this, it will be very difficult to remember lines. 

user1575: I highly suggest finding one or two openings for each side,and then playing them against computers and people until they become second nature. I personally enjoy playing the Grand Prix, Fort Knox, Dunst openings; however, those are all just my personal preferences.

user11629: In my opinion a lot depends on your level. 
For a beginner I would not recommend to learn an opening by heart. Instead focus on tactics and play openings based on general opening principles:

occupy the center
develop minor pieces
castle
don't blunder a piece to some tactics

A good indication for when you need to learn some opening theory is, if you regularly end up with slightly worse positions after the opening. (If you lose a piece or more in the opening, that would usually mean that you should improve your tactical skills instead). 

user1580: It's better to know a few good openings well, rather than a bunch of various ones. You might get thrown by some novel (to you) opening by learning a few basics, but unless you're a master who has time to learn many of them, your best defense against seemingly novel openings is good fundamentals. It will be less often that someone will be able to throw you if you focus on a few fundamental lines.

Learn the theory behind the most common openings for white that stem from e4-e5, such as Ruy Lopez or Italian game. 
Learn one of the most solid responses to 1. e4, such as the Sicilian, or maybe the Caro-Kann.
Learn the most classic responses for white to the Sicilian 
Learn the most common theory behind the most common lines after 1. d4 d5


user1606: Studying Opening Chess theory is definitively not about memorizing long lines of theory where you'll get lost if you opponent diverges...
Also what to do next once you're out of your book?
The best way is....to practice!
In a nutshell:

Study Few GMs or important games for that opening and/or system you
would like to play: you'll get a general feeling of the opening/variation, you'll 
identify tactical and strategical ideas...no opening manuals at this point!
Then Practice, Practice and Practice! (numerous blitz, 15 minutes games,
even longer time control) the more the better!
then only take a look at some opening manuals on this very specific line / system: you'll soon realized you have memorized and understood more than you =thought possible!
Rinse and repeat!

If interested, I wrote detailed post on this very topic:
http://improveyourchessornot.blogspot.ca/2013/05/how-to-study-opening.html
Hope it helps,
Cheers!

user1506: 
Write your opening down somewhere . Read it every day. Play it against real opponents / engine. Analyse your opening games, did you move the wrong piece? Try to figure out the plans of the opening. For example in c5 sicilian, one plan might be playing d5 if white played f3, because f3 is really weak after the trade-off on d5.
Just play nearly every variation and take a look at the end position. If you like it, write it down, remember it and play it. If not, discard the variation.
You need to know the plans of the opening and not only the moves. If you know the plans, you can play without knowing the moves.

It might be hard to figure out the plans on yourself, but you might find some good games of chess in the internet, which are documented / commented from a good player.

user70: In reading your question, I can't help but think you aren't asking your real question, which I read as, "When I'm out of my book I get abused.  How do I stop this from happening?"
I'm assuming that, like me, you're a USCF player rated under 1800.  I offer the following advice:

Learn two openings with White and two with Black.  Choose white openings begin with e4 or d4.  Avoid long lines where your opponent may be more booked-up.  At the amateur level, most openings and variations are playable.  Your openings with the Black pieces should be sound but off the beaten path a little.  Study games online, buy books, whatever.  Hour for hour, books are cheaper than movies. Go for it.
Find an instructor who's rated 400 or more points above you.  Ask this person to help you with your game, especially when you're out of your book.  They'll help you with applying guiding principles.  Chess principles are simple until it's time to apply them. Your instructor can help.
Don't memorize without understanding.  It is critical to understand why book moves are standard.
Don't be afraid to lose.  "I'm out of my book, I better play it safe!" is poison.


1549: <p>I'm a hobbyist chess player and usually play online. While I've seen thousands of great chess games and win a fair number of games online, the one thing that I have struggle with is studying openings. Simply put, there are just so many of them and each of them has so many variations. And to add to that, every out-of-book move my opponent makes throws me off and I don't know how to continue, so it turns out to be some hybrid/weird opening (or perhaps its a real opening with a name that I just don't know about)</p>

<p>I guess my question would be:</p>

<ol>
<li><p>What's a good way to learn some of the common/easy openings? Is it
just memorize or understanding the principles for instance, what
that particular opening is looking to achieve?</p></li>
<li><p>How do I identify which of the variations to look at for a
particular opening, there are often so many?</p></li>
<li><p>What's a good strategy to deal with my opponent suddenly going out
of book or playing a novelty in an opening that I've memorized?</p></li>
</ol>
 12402: <p>Write the various ideas that you discover in the opening. For example, in the Taimanov Sicilian against the English Attack when White attacks the Knight with g5, Black should consider playing  Nh5 and using the Knight to blockade the kingside. As you understand more and more ideas in the opening (and write them know), you'll begin to understand that it's not about memorizing moves but understanding how to respond to various plans that the opposing player can try.  That's should be your mindset when learning an opening.  Don't memorize - understand.</p>
 3872: <p>The best way, in my opinion, to learn opening theory is to study a chess database. Chessbase has a free one online, and so does chesstempo.</p>

<p>Look up games that match a particular position of your choosing. See what moves strong players play (also look at win percentages). Think about what moves you or an opponent would play in a particular position, and see how strong players respond. If there are no, or only a few games played in whatever line you are investigating, you can use a free engine, like Stockfish for example. Lastly, every time you play a game of chess, think about looking up in the database the opening that you played.  And of course, the entire time, you must try to understand why the moves are being played. If you don't do this, it will be very difficult to remember lines. </p>
 1575: <p>I highly suggest finding one or two openings for each side,and then playing them against computers and people until they become second nature. I personally enjoy playing the Grand Prix, Fort Knox, Dunst openings; however, those are all just my personal preferences.</p>
 11629: <p>In my opinion a lot depends on your level. </p>

<p>For a <em>beginner</em> I would not recommend to learn an opening by heart. Instead focus on tactics and play openings based on general opening principles:</p>

<ul>
<li>occupy the center</li>
<li>develop minor pieces</li>
<li>castle</li>
<li>don't blunder a piece to some tactics</li>
</ul>

<p>A good indication for when you need to learn some opening theory is, if you regularly end up with slightly worse positions after the opening. (If you lose a piece or more in the opening, that would usually mean that you should improve your tactical skills instead). </p>
 1580: <p>It's better to know a few good openings well, rather than a bunch of various ones. You might get thrown by some novel (to you) opening by learning a few basics, but unless you're a master who has time to learn many of them, your best defense against seemingly novel openings is good fundamentals. It will be less often that someone will be able to throw you if you focus on a few fundamental lines.</p>

<ul>
<li>Learn the theory behind the most common openings for white that stem from e4-e5, such as Ruy Lopez or Italian game. </li>
<li>Learn one of the most solid responses to 1. e4, such as the Sicilian, or maybe the Caro-Kann.</li>
<li>Learn the most classic responses for white to the Sicilian </li>
<li>Learn the most common theory behind the most common lines after 1. d4 d5</li>
</ul>
 1606: <p>Studying Opening Chess theory is definitively not about memorizing long lines of theory where you'll get lost if you opponent diverges...
Also what to do next once you're out of your book?</p>

<p>The best way is....to practice!</p>

<p>In a nutshell:</p>

<ul>
<li>Study Few GMs or important games for that opening and/or system you
would like to play: you'll get a general feeling of the opening/variation, you'll 
identify tactical and strategical ideas...no opening manuals at this point!</li>
<li>Then Practice, Practice and Practice! (numerous blitz, 15 minutes games,
even longer time control) the more the better!</li>
<li>then only take a look at some opening manuals on this very specific line / system: you'll soon realized you have memorized and understood more than you =thought possible!</li>
<li>Rinse and repeat!</li>
</ul>

<p>If interested, I wrote detailed post on this very topic:
<a href="http://improveyourchessornot.blogspot.ca/2013/05/how-to-study-opening.html" rel="noreferrer">http://improveyourchessornot.blogspot.ca/2013/05/how-to-study-opening.html</a></p>

<p>Hope it helps,</p>

<p>Cheers!</p>
 1506: <ol>
<li><p>Write your opening down somewhere . Read it every day. Play it against real opponents / engine. Analyse your opening games, did you move the wrong piece? Try to figure out the plans of the opening. For example in <code>c5</code> sicilian, one plan might be playing <code>d5</code> if white played <code>f3</code>, because <code>f3</code> is really weak after the trade-off on <code>d5</code>.</p></li>
<li><p>Just play nearly every variation and take a look at the end position. If you like it, write it down, remember it and play it. If not, discard the variation.</p></li>
<li><p>You need to know the plans of the opening and not only the moves. If you know the plans, you can play without knowing the moves.</p></li>
</ol>

<p>It might be hard to figure out the plans on yourself, but you might find some good games of chess in the internet, which are documented / commented from a good player.</p>
 70: <p>In reading your question, I can't help but think you aren't asking your real question, which I read as, "When I'm out of my book I get abused.  How do I stop this from happening?"</p>

<p>I'm assuming that, like me, you're a USCF player rated under 1800.  I offer the following advice:</p>

<ol>
<li>Learn two openings with White and two with Black.  Choose white openings begin with e4 or d4.  Avoid long lines where your opponent may be more booked-up.  At the amateur level, most openings and variations are playable.  Your openings with the Black pieces should be sound but off the beaten path a little.  Study games online, buy books, whatever.  Hour for hour, books are cheaper than movies. Go for it.</li>
<li>Find an instructor who's rated 400 or more points above you.  Ask this person to help you with your game, especially when you're out of your book.  They'll help you with applying guiding principles.  Chess principles are simple until it's time to apply them. Your instructor can help.</li>
<li>Don't memorize without understanding.  It is critical to understand why book moves are standard.</li>
<li>Don't be afraid to lose.  "I'm out of my book, I better play it safe!" is poison.</li>
</ol>
