When a Pokémon with this Ability is hit by a damaging move, there is a 30% chance that the Cursed Body will disable that move of the attacking Pokémon for 4 turns (including the turn Cursed Body activates). Cursed Body can activate even if the attacker is behind a substitute or if the Pokémon with Cursed Body is knocked out, but will not activate if the attack hits the substitute of the Pokémon with Cursed Body.
If Cursed Body disables a multi-strike move before it has finished all of its hits, it will not prevent the other hits from being executed. Cursed Body can disable a move that calls another move if the called move dealt damage.
If a Pokémon uses a damaging Z-Move on a Pokémon with Cursed Body, that damaging Z-Move can be disabled (with no effect on the base move), despite Z-Moves only being able to be used once per battle. However, if Cursed Body would disable a status Z-Move (such as Z-Nature Power), the base status move will be disabled.
When Frillish is hit by an opponent's attack that causes physical contact, Frillish's body becomes surrounded in a dark indigo aura which then covers the opponent's body. The opponent can then no longer use the move that inflicted the damage onto Frillish.
After Jellicent gets hit by an attack, Jellicent's body shakes and is surrounded by a pinkish aura. The opponent's body shakes and is surrounded by a pinkish aura in the same manner, and the attack that caused the activation is disabled.