Contact moves used against the holder will damage the attacker with 1/6 of their maximum HP. Each individual strike from a multi-strike move that makes contact will activate Rocky Helmet.
In version 1.0 of Pokémon Sun and Moon, the Rocky Helmet was involved in a glitch. If the final Pokémon of one player that was holding the Rocky Helmet was attacked by another player's final Pokémon, and both Pokémon fainted, the winner was incorrectly declared to be the Pokémon equipped with Rocky Helmet, instead of the attacker. This glitch was fixed in version 1.1.
In Under the Pledging Tree!, a Rocky Helmet was one of the items offered to Ash by a market vendor in Coumarine City after Ash had wondered out loud what presents he should buy for an upcoming festival.
Rocky Helmet was introduced as a Pokémon Tool card in the Pokémon Trading Card Game during the English Black & White Series (the Japanese BW Era) in the Noble Victories expansion. It was reprinted as both a Regular and an Ultra-Rare Secret card in the English Boundaries Crossed expansion. When this Trainer card is attached to the player's Active Pokémon, if an opponent deals damage to that Pokémon, the player can put two damage counters on the Attacking Pokémon.
