In short: A move in a known opening position that has never been played before. Strong players prepare novelties at home to surprise their opponents.
Also called theoretical novelty, TN.
In the most common openings nearly every move has been played before, often thousands of times. A move that nobody has played in a known position is called a novelty, or a theoretical novelty. In annotations it is marked TN.
Prepared at home
Before important matches and tournaments, strong players look for novelties to surprise their opponents. A good novelty can give an advantage before the game has really begun, because the opponent must find the right moves at the board while you already know the answer.
In the last game of the 2004 match for the classical world title, Vladimir Kramnik had to beat Péter Lékó. He chose an unusual line and came up with a novelty as early as move six, prepared at home. He won and kept his title: Kramnik–Lékó 2004.
When the novelty backfires
A novelty can also be wrong. In Gothenburg in 1955, three Argentinians played the same new, sharp variation of the Sicilian Defense, at the same time and against three Soviet players.
All three lost, and the variation still bears the city's name. See the game: The Gothenburg Variation.
How novelties become part of what is known about the openings is explained under opening theory.
Frequently asked questions
What does TN mean?
Theoretical novelty: a move that hasn't been played before in that position. The abbreviation is used in annotations and books.
How do you know a move is new?
You compare with collections of played games. If the move isn't there, it counts as a novelty.
Updated November 14, 2026