Forbidden and Arcanus: Item Modifiers and Special Gear
Forbidden and Arcanus lets you enhance equipment with magical modifiers applied through smithing. This guide covers the modifier system and the gear it produces.
Applying modifiers
The apply modifier recipes use a smithing template plus a special component to grant an item a new power. The components include the 
Sea Prism, 
Terrastomp Prism and 
Smelter Prism, the 
Eternal Stella, the 
Ferrognetic Mixture and the 
Soul Binding Crystal — each imparting a different effect to the gear it is applied to.
The Blacksmith Gavel
The Blacksmith Gavel is a signature tool; upgrade a Diamond Blacksmith Gavel with a Netherite Ingot through smithing to make the Netherite Blacksmith Gavel, the top tier of the tool.
Building toward the modifiers
Most modifier components are earned deeper in the mod, from its structures and rituals, so treat modifiers as a mid-to-late goal. Set up a Clibano and a rune supply first, then pursue the prisms and crystals that let you tailor your weapons, tools and armor with the effects that suit your playstyle.
Covers the mod's in-game guide topics: