Ring of the Split Mind

Alter: This crimson ring is split into two half circles that magically hover a hair's breadth apart. While wearing the ring and concentrating on only one spell, you have advantage on Concentration checks.

If you're concentrating on a spell of 3rd level or lower and wearing the ring, you can choose to cast another spell of 3rd level or lower that also requires concentration without losing concentration on the first. While concentrating on two spells in this way, make seperate concentration checks when you take damage, rolling the d20 for each spell in the order it was cast. You are vulnerable to psychic damage while concentrating on two spells in this way.

Attunement: Spellcaster
Rarity: Very Rare
Type: Ring
Cost: 29250gp

Griffons Saddlebag, Vol II