Improved Vital Strike (Combat)

You can make a single attack that deals a large amount of damage.

Source: Pathfinder d20pfsrd.com

• Prerequisites: Vital Strike, base attack bonus +11.
• Benefit: When you use the attack action, you can make one attack at your highest base attack bonus that deals additional damage. Roll the weapon’s damage dice for the attack three times and add the results together before adding bonuses from Strength, weapon abilities (such as flaming), precision-based damage, and other damage bonuses. These extra weapon damage dice are not multiplied on a critical hit, but are added to the total.