You gain Melf's Acid Arrow as a Spell-Like Ability.
Deals 2 to 8 acid damage +1 per 2 caster levels to a struck target, every 2 seconds, for a duration of 12 seconds. The arrow has double spell range and has no save.
Spell-Like Ability: This ability benefits from your Metamagic Feats without paying the normal additional spell point cost.