西洋棋的最初階段稱為「開局」。剛開始的幾個回合棋手主要關心自己的棋子是否從起始點移動到有利的位置。遊戲的初期，白方發動的一連串經過檢驗的步法稱為「開局」，而黑方回應的步法稱為「防禦」。為人熟知的開局走法有好幾十種，而其中又有好幾百種被賦予名稱的變著。《牛津西洋棋大辭典》列出了 1,327 有名稱的開局與變著，從平和的局面型走法，到激烈的戰術型走法通通包括在內。

一連串正規的步法稱為「開局步法」，一些工具書如《西洋棋開局百科》有對開局步法做了編目索引。這些工具書通常利用代數記譜法、開局樹狀圖、或開局理論表將一連串的步法呈現給讀者。如果開局偏離了「開局步法」，之後的變化就稱為「out of book」。某些開局的主線已研究到 20 到 25 步之多。有一些甚至還分析到了第 30 或 35 步，像是古印度防禦、西西里防禦中的舍文寧根變著、以及納依道夫變著。職業棋手們花費數年的時間來研究開局，而隨著開局理論不斷演進，許多棋手甚至終其一生都在研究開局。

開局中創新的走法稱為「創新理論」。有些棋手會保留這種創新的走法，直到正式比賽時才施展出來，這就叫做「預備變著」，在高等級比賽中通常會有意想不到的效果。開局分類可參見西洋棋開局列表。



開局的目標

開局方法千變萬化，但會有幾個常見的目標：讓棋子到可以影響棋局的位置、控制中心、保護國王的安全、避免兵出現弱勢、棋子適當的調度、創造比對手有利的優勢。



高等級選手的目標

第一，在高等級的比賽中，白方開局的目標通常是以保持優勢為主，而黑方的目標則是以消除白方優勢為主。因為白方有先行的優勢，假如黑方刻意模仿白方走子，白方永遠會比黑方早一步攻擊。

第二，自從 1950 年開始，另一個開局目標逐漸受到重視。根據國際大師 Jeremy Silman 的觀點，開局的目標是製造雙方的不平衡，這種不平衡進而影響到中局的情勢及棋手的進攻計畫。

第三個目標則是用來輔助前兩個目標，那就是將局面誘導到自己熟悉且偏愛的佈局，這通常是靠顛倒行棋順序來達到目的。



參考資料



延伸閱讀


* Collins, Sam. Understanding the Chess Openings. Gambit Publications. 2005. ISBN 1-904600-28-X.

* De Firmian, Nick. Modern Chess Openings: MCO-14. Random House Puzzles & Games. 1999. ISBN 0-8129-3084-3.

　
: Nick de Firmian is a three-time U.S. Chess Champion. Often called "MCO-14" or simply "MCO", this is the 14th edition of the work that has been the standard English language reference on chess openings for a century. This book is not suitable for beginners, but it is a valuable reference for club and tournament players.


* Kasparov, Garry; Keene, Raymond. Batsford Chess Openings 2. Henry Holt. 1994 [1989]. ISBN 0-8050-3409-9.

　
: Garry Kasparov is the former World Chess Champion from 1985 to 2000 and Raymond Keene is a former British chess champion. This book is often called "BCO 2" and is intended as a reference for club and tournament players.


* Lane, Gary. Victory in the Opening. Sterling Pub Co Inc. 1999. ISBN 978-0-7134-8427-4.

* Nunn, John (編). Nunn's Chess Openings. Everyman Chess. 1999. ISBN 1-85744-221-0.

　
: John Nunn is a former British Chess Champion and a noted chess author. This book is often called "NCO" and is a reference for club and tournament players.


* Sahovski Informator. _Encyclopaedia of Chess Openings_

　
: This is an advanced, technical work in five volumes published by Chess Informant of Belgrade. http://www.sahovski.com/（頁面存檔備份，存於網際網路檔案館） It analyzes openings used in tournament play and archived in _Chess Informant_ since 1966. Instead of using the traditional names for the openings and descriptive text to evaluate positions, Informator has developed a unique coding system that is language independent so that it can be read by chess players around the world without requiring translation. Called the "ECO", these volumes are the most comprehensive reference for professional and serious tournament players.


* Scheerer, Christoph. The Greatest Ever Chess Opening Ideas. Everyman Chess. 2008. ISBN 978-1-85744-561-9.

* Seirawan, Yasser. Winning Chess Openings. Everyman Chess. 2003. ISBN 1-85744-349-7.  An elementary/introductory book.

* Stefan Djuric, Dimitri Komarov, & Claudio Pantaleoni, _Chess Opening Essentials_ (4 volumes)

* Summerscale, Aaron. A Killer Chess Opening Repertoire. Globe Pequot. 1999. ISBN 978-1-85744-519-0.

* van der Sterren, Paul, _Fundamental Chess Openings_, Gambit, 2009, ISBN 978-1-906454-13-5

* Ward, Chris. The Queen's Gambit Accepted. Batsford. 1999. ISBN 0-7134-8467-5.

* Watson, John. Mastering the Chess Openings 1. Gambit. 2006. ISBN 978-1-904600-60-2.  (Three chapters of general opening principles; open and semi-open games)

* Watson, John. Mastering the Chess Openings 2. Gambit. 2007. ISBN 978-1-904600-69-5.  (Closed games and Indian defenses)

* Watson, John. Mastering the Chess Openings 3. Gambit. 2008. ISBN 978-1-904600-98-5.  (English Opening)

* Watson, John. Mastering the Chess Openings 4. Gambit. 2010. ISBN 978-1-906454-19-7.