Every time the "knucks" marble is hit, it counts one for the shooter; each time he misses in the three shots, it counts an additional shot for "knucks" when it comes his turn.
"Healthful Sports for Boys"
Alfred Rochefort
Knives and brass knucks are understood everywhere.
"Mars Confidential"
Jack Lait Lee Mortimer
There were three kinds of games at marbles which the boys played: one with a long ring marked out on the ground, and a base some distance off, which you began to shoot from; another with a round ring, whose line formed the base; and another with holes, three or five, hollowed in the earth at equal distances from each other, which was called knucks.
"A Boy's Town"
W. D. Howells