Floor Nails - A Blueholme Spell

Floor Nails: 

Range:  10  Duration:  1 turn/level

When cast floor nails sprout from the ground immediately in front of the caster.  Anyone in the general 10 foot vicinity must save vs spell or suffer 1d4 damage.  At level five the spell causes 2d4 damage.  At level 10 the spell causes 3d4 damage.  The spell is remains in effect as long as the caster concentrates (1 turn per level of caster).