Horwath
Legend
I would go with your DMs wording on this.
Imagine now a Fireball spell.
Sphere 20ft radius. In mid air it is 10667 cu ft.
What if it is detonated on the ground? Is it then 25ft radius?
What if it is detonated in the corner of the room? 40ft radius then?
Or in a narrow tunnel? 100ft in both direction?
Or at the bottom of a 10by10 deep pit? 1000ft up?
Imagine now a Fireball spell.
Sphere 20ft radius. In mid air it is 10667 cu ft.
What if it is detonated on the ground? Is it then 25ft radius?
What if it is detonated in the corner of the room? 40ft radius then?
Or in a narrow tunnel? 100ft in both direction?
Or at the bottom of a 10by10 deep pit? 1000ft up?