White has moved the king's pawn two squares and Black has replied in kind. The result is an Open Game. Other responses to 1.e4 are termedSemi-Open Gamesor Single King's Pawn Games.
When written in lowercase, the term "open game" refers to a chess position whereranks,filesanddiagonalsare open, and tending to moretacticalgameplay. It is possible that an Open Game may lead to aclosed game.[1]
White opens by playing 1.e4, which is the most popular opening move and has many strengths – it immediately stakes a claim in thecenter,and frees two pieces (thequeenand king'sbishop) for action. The oldest openings in chess follow 1.e4.Bobby Fischerwrote that 1.e4 is "Best by test." On the negative side, 1.e4 places apawnon an undefended square and weakens the squares d4 and f4. If Black keeps the symmetry by replying 1...e5, the result is an Open Game (Hooper & Whyld 1996:279) (Watson 2006:87–90).
Black's most common reply to 2.Nf3 is2...Nc6.This can lead to theRuy Lopez(3.Bb5), one of the most popular openings at all levels of chess, and one of the most extensively analyzed.
TheScotch Game(3.d4) was popular in the 19th century and remains so at amateur level. After 3...exd4 White may either recapture with 4.Nxd4, usually leading to an equal game, or play theScotch Gambit(4.Bc4), a dangerous tactical line against an unprepared opponent.
3.Nc3 Nf6, theFour Knights Game,was often played in the late 19th to early 20th century. Less commonly, 3....g6 or...Bb4, (theThree Knights Game), are possible.
ThePonziani Opening(3.c3) has never achieved widespread popularity but is occasionally used as a surprise weapon. Other third moves for White such as theKonstantinopolsky Opening(3.g3), andInverted Hungarian Opening(3.Be2) are rarely played and offer White no advantage.
Black's most popular alternative to 2...Nc6 is2...Nf6,usually leading toPetrov's Defense,though White can avoid the extensive theory of the Petrov by playing 3.Nc3.
ThePhilidor Defense(2...d6) has the disadvantage of restricting the mobility of Black's king's bishop, and typically leads to solid but passive positions for Black. For this reason, it largely fell out of favor by the early 20th century as Black players sought more dynamic options; however, it is still occasionally seen at grandmaster level.
TheGunderam Defense(2...Qe7) is an offbeat choice which blocks the development of the king's bishop, and has never achieved widespread popularity.
TheElephant Gambit(2...d5) and theLatvian Gambit(2...f5) are considered very risky for Black, with the latter usually seen only in correspondence play. TheDamiano Defense(2...f6) may be met by either 3.Nxe5 or 3.Bc4 with advantage and is almost never seen.
The most popular alternatives to 2.Nf3 are 2.f4 (theKing's Gambit), 2.Nc3 (theVienna Game), and 2.Bc4 (theBishop's Opening). These three openings have some similarities; some of the quieter lines in the Vienna and Bishop's Opening cantransposeto positional variations of the King's Gambit Declined, when White plays f2–f4 before playing Nf3. The King's Gambit was popular in the nineteenth century with grandmaster and amateur alike. White offers a pawn for speedy development, as well as to attack Black's central outpost. The Vienna Game also frequently features attacks on the Black center by means of f2–f4.
In theCenter Game(2.d4), White immediately opens the center, though if the pawn is to be recovered after 2...exd4, White must prematurely develop their queen. An alternative is tosacrificeone or two pawns by offering theDanish Gambit(3.c3).
The early development of the queen in theDanvers Opening,also known as theParham Attack(2.Qh5), is usually played only by amateurs, thoughHikaru Nakamurahas experimented with it in grandmaster tournaments and was able to achieve a reasonable position.[2][3]TheNapoleon Opening,2.Qf3, has even less to recommend it as Black can easily block any mating threats without compromising their development. ThePortuguese Opening(2.Bb5) andAlapin's Opening(2.Ne2) are offbeat tries for White, but neither gain any advantage against correct play. TheBongcloud Attack(2.Ke2) is considered a joke opening.
Bologan, Victor (October 2014).Bologan's black weapons in the open games: how to play for a win If white avoids the Ruy Lopez.Alkmaar, The Netherlands.ISBN9789056915438.OCLC878505291.{{cite book}}:CS1 maint: location missing publisher (link)
Davies, Nigel, 1960- (2005).Play 1e4 e5!: a complete repertoire for Black in the open game.London: Everyman Chess.ISBN1857444019.OCLC71338396.{{cite book}}:CS1 maint: multiple names: authors list (link) CS1 maint: numeric names: authors list (link)
Emms, John. (2000).Play the open games as Black: what to do when White avoids the Ruy Lopez.London: Gambit.ISBN1901983277.OCLC45466779.
Lokander, Martin (7 January 2016).Opening repertoire: the open games with black.London.ISBN9781781941942.OCLC922562228.{{cite book}}:CS1 maint: location missing publisher (link)