When do you need to learn openings?

No offense to the people who have offered you suggestions of opening (as those openings make sense in a way) but I don't think that is the best approach. It is not a question of 'this' or 'that' opening, but how you approach the openings in general that matters.

While you don't want to obsess over openings, it does matter which opening you choose.

If you choose a very sharp opening, with a lot of forcing lines, like the King's Gambit, you'd better be prepared - you can lose to inferior players who have seen the line pretty easily, otherwise. 

Again, I'd recommend something solid and hard to bust, like the London. YOu won't win any games out of the opening with it, and it's not as aggressive an attacking opening, but you also won't get wiped out in the opening, and more often than not will reach a very playable if not better middlegame.

If you're getting interested in learning openings, that's your cue to start learning openings.

The Colle: Move by Move by Cyrus Lakdawala (2013)

https://web.archive.org/web/20140627110453/http://www.chesscafe.com/text/hansen169.pdf

Play the London System by Cyrus Lakdawala (2010)

https://web.archive.org/web/20140627100246/http://www.chesscafe.com/text/hansen139.pdf

"... [Fundamental Chess Openings] is not particularly suited for players who are just starting out. I would imagine players rated at least 1400-1500 would get the most benefit from this volume. ..." - FM Carsten Hansen (2010)

Get your queen out but guard her!  Scare them silly!   ha ha ha 

You and me same level of chess. So I can help you out.

Personally, I study openings a lot that mid-games and endgames. I know about 37 openings perfectly. I think you should start studying openings. Two openings won't help.

There is no harm in learning openings and traps, but once you master middle and end-games. You can give time to openings as much as you'd like. At this point, what I'd recommend is you be aware of the opening traps that lies in a particular opening that you go through and some detailed variations of the lines you encounter often. Rest of the game depends on your tactical and positional play. So study tactics and positional much frequently than opening variations.

Here I will suggest what worked for me. Personally I disagree with those who say that there is no need of opening theory till 2000 elo, etc. You should study the openings. But DO NOT OVERDO IT. Give importance to the pawn structure, plans and ideas behind the moves rather than the move itself. There are thematic moves and tactics associated with each opening. Here is one other thing that I use. CORRESPONDENCE GAMES. Online chess games are very helpful in improving your openings. Choose an opening you would like to play. Get a nice book on it. Start playing online chess games on it. You actually have to get experienced with the opening before you play it well. It is during this game that you should learn the opening. Not the whole opening or book. But just the variation your opponent played. With more games, your understanding of the opening will become more profound. This way you also avoid learning some lines which are rarely played at our levels. SUPPLEMENT THIS. You should supplement these opening study, with tactics,endgame and strategy. There are lot of good tactics servers and books available. For endgame use Silman's Endgame Course. For strategy, try Simple Chess by Staen. You can choose to play opening systems like the Colle, London,etc, which are good and sidesteps theory. But in the long run it would hamper your growth as a chess player. By choosing different openings, you get more exposure to more pawn structures, strategic ideas, and thus giving rich positions where you wont always win but you will improve. Also when you consider opening books, try the ones that are based on illustrative games rather than a tree of variations. This is because, 1. It is more enjoyable and you wont regret studying t.

2. You can understand the middlegame plans which unfold in your openings.

Ok, no offense but this is what I don't get.  If you know about 37 openings perfectly, why is your rating in the 1500's?   Fischer said that chess is dead because everybody is just memorizing moves.  Then came chess 960.  I am a low rated player and maybe that is because I don't care about openings.  Or maybe not.  Some people play for years and never get better.  Its all in the brain...not in the opening.

@xming

You said "people play for years and never get better. Its all in the brain...not in the opening." You mean I am playing for years and did not improve?? My rating is 1529 in online chess. That takes months to complete a game. And of course, I got a rating of 1289 to 1336 in two days just by 15-19 games of blitz.

Opening isn't everything. I am not a so good positional player so my rating stays at 1500's. But definitely everyone can improve and even I will improve.

Steikt, sorry I went off topic.

Same for me.

@OP
If you want to memorize, then I'd say just memorize a single main line,15, 20, or more moves deep. It could even be a whole game. Just to serve as an anchor.

But then the important part, learn the middlegame ideas. Play over 10 or 20 games which include all different variations for that line. Don't make any effort to memorize the moves, you just want the general ideas and themes. Try to use games from as few players as possible (one specialist for that opening is ideal if you can find a strong GM)

Later when you want to review the opening, review those games. Interact, don't just mechanically play through them. Write down questions and explore any lines you think are interesting. You can also add more games as you go.

When masters and above talk about no need to know openings, I think they're not telling you the whole story. You don't need to memorize the opening moves... but you do need to know the middlegame ideas, because then you will often find book moves on your own.

I'm rated ~1950 and I'm usually out of book before move 10 AFAIK during the game. But when I get home it's not terribly rare to see I followed book (or played reasonable moves that someone has tried before) for 15 or more moves.

I've only now started to work on memorizing more than one main line because I'm too often falling behind on the clock before move 20.

@Harish73...I accepted  your challange and got a message you were on vacation???

I know you will get better.  Its easy to go from a rating of 1000 to 1500.  Its not so easy to go from 1500 to 1800, so I've been told.

Thank you all for taking the time to answer my question 

@LeBellman. First time Romantic second time Grinder.

@HolyKing. I have started playing a lot more daily chess games. When I started playing chess I only played blitz games

I think I'm going to try London and Colle now and see what I think. I need to learn more openings and don't just play e4.

Who's games should I look at? Who played for example London and Colle a lot?

I have looked a little bit at the london and colle now. I must say I'm a little bit uncomfortable playind 1.d4 since I only play 1.e4. But I guess it's good to try something new.

Is there any good e4 openings I should try?

I'm an e4 player as well. The d4 system openings like the London are OK but it depends upon what you want to achieve and how much work you are willing to invest. If you haven't got the time then d4 system openings are good, but if you are willing to invest time (years) then taking on a full opening rep is probably the better long term option. Depends upon your goals.

One can find a lot about 1 e4 possibilities in the books that I previously mentioned:

Discovering Chess Openings by GM John Emms (2006)

https://web.archive.org/web/20140627114655/http://www.chesscafe.com/text/hansen91.pdf

Openings for Amateurs by Pete Tamburro (2014)

http://kenilworthian.blogspot.com/2014/05/review-of-pete-tamburros-openings-for.html

I believe that it is possible to see a fair portion of the beginning of Tamburro's book by going to the Mongoose Press site.

It is another 1 d4 possibility, but, if one wants to read about the Colle-Zukertort, one can try: Starting Out: d-Pawn Attacks by Richard Palliser (2008)

https://web.archive.org/web/20140626165651/http://www.chesscafe.com/text/hansen118.pdf