Increases damage by 50%, but only of the 'variable' part, so the 1d4 and not the +1 (I think).<br/><br/>In general, not that good for MM, increases average from 3.5 to 5.25 per missile. Pretty weak for a third level spell. (Even if it does apply to the +1).<br/><br/>Scorching Ray is a L2 spell that would do much higher damage (though it requires a ranged touch attack and is subject to fire resistance).<br/><br/>Empower's good for fireball, lightning bolt, etc.