The Headband of Intellect is a piece of magical headwear that augments the wearer's intelligence.
The Headband of Intellect's design is that of a very thin golden circlet. It has like a spiral design at the base of the center piece, and there's a slight bit of a green gem that's fixed in the center, and it just rests across the brow.
Once they attune to the item, a Headband of Intellect sets the wearer's Intelligence score to 19. It has no effect if the wearer's Intelligence is 19 or higher without it.
In 836 P.D., the Mighty Nein ventured into the Heirloom Sphere (aka the Happy Fun Ball of Tricks) to rescue Yussa Errenis after he had failed to return from his last excursion inside. After being pursued and cornered by an anti-magic golem and destroying it through spells and arcane cannons, the party discovered two items: a rod and a circlet. Caleb Widogast identified the items as the "Rod of the Solitary Scout" and the "Headband of Intellect".
Behind the scenes
The Headband of Intellect is a magic item in Dungeons & Dragons 5th Edition that first appeared in the Dungeon Master's Guide, which was published in November 2014.
Mechanically speaking, the Headband of Intellect is categorized as a Wondrous item of uncommon rarity. It requires attunement, and it sets the wearer's Intelligence score to 19, but has no effect if their Intelligence score is higher without it.