Overview
Dekopin (デコピン) is the act of flicking someone's forehead with their finger. It translates to "forehead flick" in English.
Flicking consists of bending a finger and holding it in place with the thumb then releasing the finger with built-up force to hit the forehead. The middle finger is said to produce more force.
The flick is said to produce a modest force even with just the tip of a finger. In some cases, it's been used as a small punishment, but there are cases of the flick being used on infants with fatal results.
It is often used as a comic gimmick in Japanese media. Like when a boke (fool) makes a dumb statement and a tsukkomi (straight-man) gives them a flick to the head as a remark. Or it can be used as "the strongest-weakest attack."
