Prerequisites: Str 15
Benefit: When making a melee attack, you can take a −2 penalty to the attack roll. If the attack hits, you gain a +2 bonus to the damage roll (or a +3 bonus to the damage roll with a two-handed weapon). This extra damage increases by level, as shown on the table below, but the attack penalty remains the same.[PH:199]
|Power Attack Damage|
While the damage bonus may be nice, the average damage per round gained is somewhere between 0.5 (heroic tier) and 2.5 (at epic tier), assuming that you would hit on a natural die roll of 10. The bonus quickly fades on hard-to-hit targets or if using an encounter power and a hard-hitting weapon. There is more often than nor a more reliable means to inflict additional damage.
If you can get accuracy high enough to consistently hit on a low die roll, feel free to take the feat. Otherwise, it's not a worthwhile investment.