20x20 would be 16 squares.
20ft RADIUS (if I remember the spell correctly, I'm on my phone) is 40x40.
20x20 would be 16 squares.
20ft RADIUS (if I remember the spell correctly, I'm on my phone) is 40x40.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.