Earthstrike Quake

(Tome of Battle: The Book of Nine Swords, p. 82)

Stone Dragon (Strike)
Level: Crusader 8 (Two Stone Dragon maneuvers), Swordsage 8 (Two Stone Dragon maneuvers), Warblade 8 (Two Stone Dragon maneuvers),
Casting Time: 1 standard action
Range: 20 ft.
Area: 20-ft.-radius burst, centered on you
Duration: Instantaneous
Saving Throw: Reflex negates

You swing your weapon in a wild arc, slamming it into the ground at your feet. Energy surges out from you, causing the ground to shudder with a sharp tremor.

You channel ki into the earth with your mighty strike, causing the ground to rumble and shake briefly. Anyone standing on the ground in this maneuver?s area must make a successful Reflex save (DC 18 + your Str modifier) or be knocked prone. Any creature standing on the ground in this area that is currently casting a spell must succeed on a Concentration check (DC 20 + spell level) or lose the spell.

You are immune to the effect of the earthstrike quake maneuver. Your allies must still save as normal against its effect.

Walls and similar barriers don?t block the line of effect of an earthstrike quake.