Attack Bonus
From D20advanced
Your attack bonus represents overall combat ability. You add your attack bonus to your attack rolls to determine if you hit a target in combat. (For more on attack rolls and combat in general, see Chapter VII: Combat).
Your ranks in the appropriate Weapon Group skill (or in some cases FX ranks) determine your attack bonus with a given attack. A rank in the Weapon Group skill for any given type of weapon costs 1 character point per rank. Power level limits your maximum attack bonus.

