Other forms: slaps on the wrist
If you're caught breaking the rules, you'll probably hope for a slap on the wrist: a punishment that is remarkably small or mild compared to the severity of the offense.
A slap on the wrist refers figuratively to any kind of minor penalty that doesn't match the seriousness of a crime. It implies that someone "got off easy," avoiding much harsher consequences. For example, being sentenced to paying a small fine or to performing community service — instead of the maximum sentence of a year in juvenile detention! — would be considered a slap on the wrist. You can remember its meaning by picturing the difference between a light, corrective tap on the hand and a truly severe, life-altering legal judgment.