Are there any known instances of identical games having been played? I realize the odds are extremely against it but I was thinking that the odds would probably be greatly reduced when players focus on heavily played openings and defences.
Not only have identical games occurred, identical forum threads have been started.
This 7 year old thread cites a game that has reportedly been played 386 times.
http://www.chess.com/forum/view/general/no-two-games-alike
This is just theoretical, but the position that all beginner players create after a Scholar's Mate has been repeated a fwe thousand times. The beginners have a tendency to always move the a-pawn all the way up, so it's a widely repeated position.
This is the game mentioned previously. According to Chessbase, there are now 1512 games in their database.
By identical I mean just that, every move from beginning to end. Obviously openings and endings will likely repeat but is there a recorded instance of a truly identical game being played at some point in history?
A more interesting question if it were any games over 40 moves that were identical
By identical I mean just that, every move from beginning to end. Obviously openings and endings will likely repeat but is there a recorded instance of a truly identical game being played at some point in history?
The list of identical 11 move games goes on for 15 pages.
Yes.
Ivanchuck-Carlsen in Tata Steel 2015 and Topalov-Anand Norway Chess 2015 are the exact same game.nn
Looks familiar? 
IM Luis Rodi explains, "Black loses a pawn since Qxb5 is answered by Ba4 and Bxd7. The database contains numerous games with this exact position and disaster, including.... Hou Yifan-Granda Zuñiga (Merida, 2008), in which the Peruvian resigned in the exact same position!
On the stage, the top-seed was stunned after 16.Nxb5 and stared at the board for nearly ten minutes. He finally shook out of it and with a wry laugh resigned.
ive seen the same scholars mate in probably thousands of juniors games...
Believe it or not I have replicated the game of Morphy against my very strong friend who don't read chess literature. He was impressed because I checkmated him spectacularly in his Philidor's defence. Below is the game until checkmate. Very funny and amusing. This is the only game I remember on my experience which was replayed. I explained to him and he was like, "what?! Are you serious?!"
"Fool's Mate" must have been played identically countless times.
Regarding the Morphy Opera game, have a look at this game on chessgames. Its an exact replay. Rene Gralla,who played white, has posted in the comments section.
http://www.chessgames.com/perl/chessgame?gid=1578394
Also another game here which deviates at move 14.
http://www.chessgames.com/perl/chessgame?gid=1704602
There was once a featured game of Carlsen in chessbase.com where Carlsen(being white) was following a game which ends up with perpetual check on the K-side. The perpetual check was not done by Carlsen, instead what Carlsen did was continue the drawish game and Carlsen won. I forget the name of the tournament and the oppponent. The game was between 2006 to 2009, where Carlsen was the newly minted World Champ during that strange game.
Are there any known instances of identical games having been played? I realize the odds are extremely against it but I was thinking that the odds would probably be greatly reduced when players focus on heavily played openings and defences.