Play for keeps is an idiom that has been in use for over 150 years. We will examine the meaning of the common idiom play for keeps, where it came from, and some examples of its idiomatic usage in sentences.
To play for keeps means to be ruthless, to proceed seriously and without mercy. When someone plays for keeps he is committed to emerging victorious, at all cost. The expression play for keeps came into use around 1860 and refers to a certain way to play with marbles. In ruthless games, the marble players play for keeps– meaning that the victor gets to keep all the marbles he has won from his opponent during the game. Related phrases are plays for keeps, played for keeps, playing for keeps. The idiom is often shortened to simply: for keeps.
During the 76ers’ three scrimmages, Brett Brown said he learned a lot about his team as it gets ready to play for keeps. (Philadelphia Inquirer)
“I honestly warned him, the Republicans in the U.S. Senate and the House, they don’t play. They’re not like Republicans in the state Legislature — they play for keeps,” Cárdenas said. (Sacramento Bee)
What the prosecutors in this case underestimated was that Aaron Swartz played for keeps too and found a way to leave this world as an innocent man … but what a price. (Forbes)