Arcane

Arcane is a spell type, a subtype seen exclusively on instants and sorceries. It is like a creature type in that it does not affect the casting of the spell, but there are several cards that interact with Arcane cards, most notably the cards with splice and Spiritcraft. The Arcane spell type was introduced in Champions of Kamigawa and marks spells cast by the numerous spirits of that plane. In this sense, Arcane was a precursor to tribal spells.