This beetle-shaped medallion provides three benefits while it is on your person.
Defense. You gain a +1 bonus to Armor Class.
Preservation. The scarab has 12 charges. If you fail a saving throw against a Necromancy spell or a harmful effect originating from an Undead, you can take a Reaction to expend 1 charge and turn the failed save into a successful one. The scarab crumbles into powder and is destroyed when its last charge is expended.
Spell Resistance. You have Advantage on saving throws against spells.
+1 AC; Advantage on saving throws against spells. 12 charges: fail a save against a NECROMANCY spell or a harmful effect from an Undead and you can take a Reaction to expend 1 charge and turn that failure into a success. Destroyed when the last charge is spent.
RollQuest ships the D&D 2024 SRD as a content pack, on a 5e character sheet that does the maths - roll from the sheet and let the numbers work themselves out. Free to start.