Is opening theory essential?

I've been playing chess now for about a month, great game,very addictive, wish I discovered the game years ago. I am now getting the basics of the game e.g development, castling ect. Now I've learned something new this week about chess...the openings e.g the sicilian defence, the kings gambit, the queens gambit ect. The amount of opening theory is quite overwhelming for a person as lazy as me. Is it essential to know opening theory? can you survive without it?

At our level, I think one should decide what first few moves to consistently play and stick with it, e.g.

As white,  choose one of 1. d4, e4, Nf3 or c4

As black, figure out the first few moves to respond to each of the above.

At your level there is no need to worry...learn...be concerned about knowing opening theory.  All you need is the opening principles:

Control the center

Develop toward the center

Castle

Connect your rooks (move the queen)

But of course that final decision is up to you.  

Yeah at your level, all you need is opening principles. Focus on reducing making simple blunders,solve tactics problems. Study middlegames and endgames too.

"... For players with very limited experience, I recommend using openings in which the play can be clarified at an early stage, often with a degree of simplification. To accomplish this safely will take a little study, because you will have to get used to playing wiith open lines for both sides' pieces, but you can't eliminate risk entirely in the opening anyway. ... teachers all over the world suggest that inexperienced players begin with 1 e4. ... You will undoubtedly see the reply 1 ... e5 most often when playing at or near a beginner's level, ... After 2 Nf3, 2 ... Nc6 will occur in the bulk of your games. ... I recommend taking up the classical and instructive move 3 Bc4 at an early stage. Then, against 3 ... Bc5, it's thematic to try to establish the ideal centre by 4 c3 and 5 d4; after that, things can get complicated enough that you need to take a look at some theory and learn the basics; ... Of course, you can also play 1 d4 ... A solid and more-or-less universal set-up is 2 Nf3 and 3 Bf4, followed in most cases by 4 e3, 5 Be2 and 6 0-0. I'd rather see my students fight their way through open positions instead; however, if you're not getting out of the opening alive after 1 e4, this method of playing 1 d4 deserves consideration. ... a commonly suggested 'easy' repertoire for White with 1 Nf3 and the King's indian Attack ... doesn't lead to an open game or one with a clear plan for White. Furthermore, it encourages mechanical play. Similarly, teachers sometimes recommend the Colle System ..., which can also be played too automatically, and usually doesn't lead to an open position. For true beginners, the King's Indian Attack and Colle System have the benefit of offering a safe position that nearly guarantees passage to some kind of playable middlegame; they may be a reasonable alternative if other openings are too intimidating. But having gained even a small amount of experience, you really should switch to more open and less automatic play." - IM John Watson in a section of his 2010 book, Mastering the Chess Openings, Volume 4

No.

You need to experiment with open games at this stage of your chess career but you do need to have an opening repertoire at some point -- approximately 1800 ELO. May I suggest something to look into when you want something to spice up your 1.e4 e5 response? I'm talking about the Scandinavian Defense 3...Qd6 Variation which is GM tested. Join us to get the inside story at http://www.chess.com/groups/view/scandinavian-defense-3qd6-variation

The primary purpose of the 2006 book, Discovering Chess Openings, was to discuss basic opening principles, but, along the way, author, GM John Emms, did give some information about various specific openings. At one point, he wrote, "If you find an opening here that appeals to you and you wish to find out more about it, the next step would be to obtain an introductory text devoted entirely to that subject."

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

"Throughout the book Emms uses excellently chosen examples to expand the readers understanding of both openings and chess in general. Thus equipped the student can carry this knowledge forward to study individual openings and build an opening repertoire. ... For beginning players, this book will offer an opportunity to start out on the right foot and really get a feel for what is happening on the board." - FM Carsten Hansen

Opening theory is NOT essential for anyone below master, as they are useless. However, opening ideas, and knowing some opening plans are very essential. This has been misunderstood by plenty of players.

"... a good opening book can open up new vistas that you would probably not discover for yourself. ... I feel that the main reasons to buy an opening book are to give a good overview of the opening, and to explain general plans and ideas. ..." - GM John Nunn (2006)

Been playing for a month? Nope.

let's hear some more. so far so helpful for someone of my skill.

What exactly is "opening theory"? Heuristics? Opening books alone?

You *must* know heuristics to play well since without those you will be playing by sheer tactics alone, like a low-rated computer program, and will gradually slide into a bad position as low-rated programs do. I consider well-studied opening moves to be the result of heuristics, as well.

I advocate studying everything at once, spread out evenly in small doses: openings, heuristics, plans, endgames, tactics, and anything else.