The Destiny Knot is a fairly useful held item in the Pokémon series not so much because of its in-battle utility, but rather its efficiency in breeding Pokémon with good IVs. If one Pokémon holds the Destiny Knot while being bred with another, five of the two Pokémons’ 12 total IVs (every Pokémon has six IVs) are guaranteed to pass down to the child; if both Pokémon have good IVs, the child will as well.
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