You are adept at using acid-based spells to melt your foes, granting you the following benefits:

• You spellcasting ability score increases by (if you use multiple ability scores for spellcasting, choose one of them to increase).
• Once per turn, when you deal acid damage to a creature with a spell of 1st level or higher, you can cause that creature to start melting. Until a creature uses an action to wash the acid away with water, a melting creature takes 1d4 acid damage at the start of each of its turns.
• When you score a critical hit with a spell that deals acid damage to a creature, you can cause each creature within 5 feet of the target to take acid damage equal to your proficiency bonus + your spellcasting ability modifier.