Empower Spell-Like Ability( Monster Manual v.3.5, p. 303)
A creature with this feat can use a spell-like ability with greater effect than normal.
Spell-like ability at caster level 6th or higher,
The creature can use one of its spell-like abilities as an empowered spell-like ability three times per day (or less, if the ability is normally usable only once or twice per day). When a creature uses an empowered spell-like ability, all variable, numeric effects of the spell-like ability are increased by one-half. An empowered spell-like ability does half again as much damage as normal, cures half again as many hit points, affects half again as many targets, and so on as appropriate. For example, a phoelarch's empowered scorching ray deals 1-1/2 times normal damage (roll 4d6 and multiply the result by 1-1/2 for each ray). Saving throws and opposed rolls (such as the one made when a character casts dispel magic) are not affected. Spell-like abilities without random variables are not affected. The creature can only select a spell-like ability duplicating a spell with a level less than or equal to half its caster level (round down) -2. For a summary, see the table in the description of the Quicken Spell-Like Ability feat on the next page. For example, a creature that uses its spell-like abilities as a 13th-level caster can only empower spell-like abilities duplicating spells of 4th level or lower.
This feat can be taken multiple times. Each time it is taken, the creature can apply it to a different one of its spell-like abilites. empower Spell-Like Ability. Spell -- Caster. Level -- Level. 0 ------ 4th. 1st ----- 6th. 2nd ----- 8th. 3rd ---- 10th. 4th ---- 12th. 5th ---- 14th. 6th ---- 16th. 7th ---- 18th. 8th ---- 20th. 9th -- --.