FIDE Laws of Chess
6: The chess clock
'Chess clock' means a clock with two time displays, connected to each other
in such a way that only one of them can run at one time.
the Laws of Chess means one of the two time displays.
means the expiration of the allotted time for a player.
Each time display has a 'flag'. Immediately after a flag falls, the requirements
of Article 6.2(a) must be checked.
When using a chess clock, each player must make a minimum number of moves
or all moves in an allotted period of time and/or may be allocated an additional
amount of time with each move. All these must be specified in advance.
The time saved by a player during one period is added to his time available
for the next period, except in the 'time delay' mode. In the time delay
mode both players receive an allotted 'main thinking time'. Each player
also receives a 'fixed extra time' with every move. The countdown of the
main time only commences after the fixed time has expired. Provided the
player stops his clock before the expiration of the fixed time, the main
thinking time does not change, irrespective of the proportion of the fixed
Before the start of the game the arbiter decides where the chess clock
At the time determined for the start of the game the clock of the player
who has the white pieces is started.
If neither player is present initially, the player who has the white pieces
shall lose all the time that elapses until he arrives; unless the rules
specify or the arbiter decides otherwise..
Any player who arrives at the chessboard more than one hour after the scheduled
start of the session shall lose the game unless the rules of the competition
specify or the arbiter decides otherwise.
A flag is considered to have fallen when the arbiter observes the fact
or when either player has made a valid claim to that effect.
During the game each player, having made his move on the chessboard, shall
stop his own clock and start his opponent's clock. A player must always
be allowed to stop his clock. His move is not considered to have been completed
until he has done so, unless the move that was made ends the game. (See
Articles 5.1, and 5.2) The time between making
the move on the chessboard and stopping his own clock and starting his
opponent's clock is regarded as part of the time allotted to the player.
A player must stop his clock with the same hand as that with which he made
his move. It is forbidden for a player to keep his finger on the button
or to 'hover' over it.
The players must handle the chess clock properly. It is forbidden to punch
it forcibly, to pick it up or to knock it over. Improper clock handling
shall be penalised in accordance with Article 13.4.
If a player is unable to use the clock, an assistant, who is acceptable
to the arbiter, may be provided by the player to perform this operation.
The clocks shall be adjusted by the arbiter in an equitable way.
Except where Articles 5.1 or one of the Articles 5.2 (a), (b) and (c) apply,
if a player does not complete the prescribed number of moves in the
the game is lost by the player. However, the game is drawn, if the position
is such that the opponent cannot checkmate the player's king by any possible
series of legal moves, even with the most unskilled counterplay.
Every indication given by the clocks is considered to be conclusive in
the absence of any evident defect. A chess clock with an evident defect
shall be replaced. The arbiter shall use his best judgement when determining
times to be
shown on the replacement chess clock.
If both flags have fallen and it is impossible to establish which flag
fell first, the game shall continue.
If the game needs to be interrupted, the arbiter shall stop the clocks.
A player may stop the clocks only in order to seek the arbiter's assistance,
for instance when promotion has taken place and the piece required is not
The arbiter shall decide when the game is to be restarted in either case.
If a player stops the clocks in order to seek the arbiter's assistance,
the arbiter shall determine if the player had any valid reason for doing
so. If it is obvious that the player has no valid reason for stopping the
player shall be
penalised according to article 13.4.
If an irregularity occurs and/or the pieces have to be restored to a previous
position, the arbiter shall use his best judgement to determine the
times to be
shown on the clocks. He shall also, if necessary, adjust the clock's move
Screens, monitors, or demonstration boards showing the current position
on the chessboard, the moves and the number of moves made, and
also show the number of moves, are allowed in the playing hall. However,
the player may not make a claim based on information shown in this manner.