A jinx was a type of dark spell. The effects of a jinx were irritating, but fun. As a minor form of dark magic, jinxes had the least severe effects of the three dark spells. Hermione Granger on the practical uses of jinxes

 To perform a jinx successfully, the caster must maintain eye contact with the target.

 Jinxes can also be used in a defensive capacity, and thus Defense Against the Dark Arts students learned some such as Knockback Jinx and Impediment Jinx. .

 Jinx effects can be blocked or removed with an anti-jinx or an anti-curse and can be prevented with an anti-jinx. The first category was taught in the Defense Against the Dark Arts class, while the second was probably part of several protection charms and thus was mostly covered in the Charms class.

 In the event of major jinx effects, such as reversals and irreversible effects, wizards should allow themselves to be treated at St. Mungo's Hospital for magical damage, or at least by any healer or expert in the knowledge of dark magic.