There has been a lot of debate in my D&D group about the specific wording of Dispel Magic which were not answered by the D&D Sage Advice Compendium:
Choose one creature, object, or magical effect within range. Any spell of 3rd level or lower on the target ends. For each spell of 4th level or higher on the target, make an ability check using your spellcasting ability. The DC equals 10 + the spell’s level. On a successful check, the spell ends.
What happens if one chooses a "magical effect"?
In a similar question I asked whether or not Dispel Magic could target multiple effects on a single creature or object: How exactly does the Dispel Magic spell work with multiple effects?
The answer there was that Dispel Magic does have a plural effect (it can remove more than one effect with a single casting). If this is the case, then I'm left to question what exactly is meant by targeting a "magical effect".
Targeting a creature is obvious. Remove all spells on that creature.
Targeting an object is similarly obvious. Remove all spells on that object.
However could I, for instance, target the magical effect of "Invisibility" and remove all instances of Invisibility within a 60-foot radius of the caster? Could I target "Glyph of Warding" and remove all glyphs in the area?
Best Answer
You only target one specific Effect, not all instances of an Effect of a certain type
You seem to be misunderstanding what it means by 'Magical Effect.'
Your interpretation of it is "A type of magical thing that is happening."
The actual meaning is "A Single, Discrete Magical Thing that is NOT a Creature or Object." You can't use Dispel Magic as an AoE Spell Purge to burn out all instances of a particular spell.
PHB201
When it refers to a Magical Effect, it is talking about things like Wall of Fire, Storm of Vengeance, Illusions, and so on. An individual instance of magic that is not attached to a creature or object. If that targeting option didn't exist, you couldn't Dispel effects like that, because a spell like Earthquake is neither a creature nor an object.
The target required by Dispel Magic is a specific target. Either 1 Creature, 1 Object, or 1 Magical Effect. You cannot target a type of magical effect.
And to give an actual Sage Advice quote...