The victim of a confidence game is often called the mark, or the vic. This is an underground slang term that evolved amongst swindlers because the intended victim was said to be "marked" for the sting.

In some instances the victim would literally be marked; such was a practice among traveling crooked carnival game mobs who were known to hit towns, set up an amusement park and leave after a few days. When one of the operators was done working a victim he would give him a friendly tap on the shoulder and wish him better luck next time. The real purpose of the gesture was to leave a dusty chalk mark, or a sticker, that operators of other games would recognize to mean that this mark has particularly good potential.