Thunder Field

School: evocation [sonic]
Circle: bardic 4th
Spell Components: V, S
Action Time: 1 action
Range: medium
Shape: radius (medium)
Targeting: all (radius)
Base Duration: instant
Saving Throw: fortitude half
Spell Resistance: yes
Ritual Components: n/a

Causes a cacophonous field to manifest over the target area, dealing 1d8 sonic damage/round and knocking those who fail their Fortitude save off-balance, or prone if they were already off-balance for 2d3+1 rounds.