The Best Items in Act 1 Underdark in Baldur's Gate 3
Luminous Armour
Luminous Armour lets the caster create a Radiant Shockwave when dealing Radiant damage. This can be great for example for clerics casting that one guiding bolt spell. This fine chest can be obtained when first entering the Underdark through the Selunite outpost. You need to pass a Perception DC 15 check on a fake wall, then disarm the trapped chest and find it within. On my playthrough there was a disarm trap kit in a box nearby in the same room. If you don’t pass the perception or otherwise need another method, you can Misty Step, for example using the Misty Step Amulet obtained on the way down here in Princess Gut’s room. It also provides armour class of 15 which is 2 higher than Shadowheart’s base armor which is nice.
Phalar Aluve
Phalar Aluve. A certain sword that must be pulled out of a stone. After first entering Underdark from Selunite Outpost, turn left and walk over to this at X:111 Y:-189. You can use a strong character to pass a strength (DC 15) check or one with high intelligence to pass the religion (DC 10) check.
Starting the buff takes an action so it’s ideal to enter turn-based mode and start it right before combat begins. There are two different versions of buff:
Sing: Allies have 1d4 bonus to attack rolls and certain saving throws.
Shriek: Enemies take extra 1-4 thunder damage and have penalty to certain saving throws.
Boots of Speed
The Boots of Speed are quite handy for using bonus action dash to get around especially for a melee class. Get them from the gnome Thulla in the Ebonlake Grotto (mushroom village), give her an antidote or potion of sylvanus.
Melf's First Staff
Melf's First Staff is nice. It can be bought from Blurg in Ebonlake Grotto (mushroom village).
Psychic Spark
Psychic Spark is nice for getting an extra dart with magic missile, and a free cast, especially for any caster optimizing for this type of multiple small hit damage. Also handy for the hag even otherwise, or interrupting spell concentration.