Overloading (also overworking) is a

chess tactic In chess, a tactic is a sequence of moves that each makes one or more immediate threats ─ that is, a check, a material threat, a checkmating sequence threat, or the threat of another tactic ─ which culminates in the opponent being unable to ...

in which a defensive piece is given an additional defensive assignment which it cannot complete without abandoning its original defensive assignment.

Examples

Krasenkow–

Karpov Karpov (russian: Ка́рпов) is a surname. Notable people with the surname include: * Aleksandr Karpov, Soviet ace, double Hero of the Soviet Union * Anatoly Karpov (born 1951), Russian chess grandmaster, Undisputed World Chess Champion 1975� ...

, in the first round of the 2003

Corus chess tournament The Tata Steel Chess Tournament is an annual chess tournament held in January in Wijk aan Zee, the Netherlands. It was called the Hoogovens Tournament from its creation in 1938 until the sponsor Koninklijke Hoogovens merged with British Ste ...

, reached the diagrammed position with Black to play. As the white rook on f1 is preventing the black queen from giving checkmate by capturing the pawn on f3, Black won immediately with :29... Re1 further pinning the white rook against the king and overloading the rook. White now cannot prevent the black queen from taking the f-pawn: if White tries to protect the rook with 30.Rxe1 or 30.Qc4, then 30...Qxf3. If White sacrifices the rook by playing 30.Kg2, then 30...Rxf1 31.Kxf1 Qxf3+ and loses the other rook with 32...Qxd5.
In

Liviu-Dieter Nisipeanu Liviu-Dieter Nisipeanu (born 1 August 1976) is a Romanian (until 2014) and German (since 2014) chess grandmaster. His peak FIDE rating was 2707 in October 2005, when he was ranked fifteenth in the world, and the highest rated Romanian player ev ...

– Anish Giri (see diagram), Giri (Black) played :30... Bxh3 overloading the g2-pawn, as 31.gxh3 is met with 31...f3 32.Re3 Qg5+. After 31.Qc3 Bg4, Nisipeanu resigned. An overload was also used in Rotlewi versus Rubinstein.

References

Chess tactics Chess terminology {{chess-stub