How to dispel greater invisibility in D&D 5E?
Invisibility in a Dungeons and Dragons 5th edition game has one major advantage over most other forms of invisibility in video games, which is that the player can still perform actions without breaking their cover. On the other hand, spells like Phantasmal Force will render a character completely invisible while at the same time making them act on their turn. This is not common with true invisibility effects such as gaseous form.
Phantasmal Force – Roughly speaking this spell mimics what an entirely harmless creature might do if it inhabits your space. A target of this spell follows simple instructions given by you, and moves about your space according to those instructions (provided that following such instructions does not require it to do anything obviously dangerous or of which you would not normally do yourself).
If a creature succeeds on its saving throw, the target treats all creatures as having total concealment for the duration of the spell. This spell is quite likely to cause death and injury by using it in dangerous areas, so I’d recommend against that unless you really know what you are doing.
Unfortunately, at least in my experience this spell does not allow the caster to act during the illusion. They must wait until their turn to take advantage of invisibility granted by Phantasmal Force .
It isn’t possible to dispel magic of magnitude greater than your level using counterspells, specifically for greater invisibility. Greater invisibility is an 8th-level spell which means it’s beyond the power of a 3rd level counter spell. Instead, wizards would need to find an anti-invisibility magical item such as a “Folding Mirror” or “Helm of True Seeing”, or another wizard who can cast dispel magic at that magnitude. Alternatively, there are some weapons and other items with special properties against invisible creatures.”
If your DM approves, this would be a great opportunity to recreate Humphrey Bogart’s movie rendition of the invisible man. You can find a tutorial on Youtube that teaches the audience how to make their own goggles with an old two liter bottle and chicken wire. Then as you venture through D&D, just pretend the bad guys are making eye contact with thin air as you watch from another dimension! :x)