Chekhov’s Gun

Chekhov's Gun
A rifle that is hung on the wall in the first act of a play must go off in the second or third act.
Chekhov's Gum
Gum that is visibly chewed in the first act must appear stuck to the sole of someone’s shoe in the third.
Chekhov's Sun
If the sun sets before the action of the play begins, it should rise in the third act, just in time to turn the vampire antagonist to ash.
Chekhov's Bun
Any baked good that is eaten in the first act should be found to have left crumbs in an inconvenient location in the second or the third.
Chekhov's Hun
A Eurasian nomadic leader who comes to power in 434CE must conquer substantial parts of Western Europe by 453CE.
Chekhov's Drum
A percussion instrument that is given to a small child in the first act will have driven the adult characters in the play insane by the third.
Chekhov's Mom
Yevgeniya Yakovlevna Morozova Chekhova (1835-1919)
Chekov's Phaser
A personal energy weapon issued to Ensign Pavel Chekov of the USS Enterprise. It may be fired at any time that the plot demands it.
Chekhov's Gnu
A large African antelope, sometimes referred to as a wildebeest. The animal in question was the property of the playwright Anton Chekhov and a family pet popular with the children of his sister Maria Chekhova.