Slayer deeds were added in January 2018 to create a new method for players to apply a slayer property to runic weapons. They are available via the Tinkering menu and can only be applied to runic blacksmith weapons. Unlike normally crafted slayers, the deed applies a limited number of slayer charges to the runic weapon and will break when the charges are exhausted. 120 Tinkering is required to be able to create these deeds.
Slayer deeds are also usable on wooden crafted weapons as long as they have at least two magic attributes.