Combat Ability is a numerical representation of how capable a character is in combat. A character's Combat Ability can be split up into four different areas: Attack, Defense, Counter, and Speed. Each contribute to combat in different ways.
Characters can modify how their Combat Ability is split up every round at the beginning of their turn.
The Base Attack Bonus, also referred to as the "BAB," is the portion of a character's Combat Ability that gets applied towards the character's attack roll.
A character's BAB represents his focus on attacking, allowing him to land blows on his opponents more often.
The Base Defense Bonus, also referred to as the "BDB," is the portion of a character's Combat Ability that gets applied towards defense. This value is added into the character's Armor Class.
The BDB effectively represents how focused a character is on protecting himself, allowing him to anticipate, dodge, and avoid attacks with more ease.
Characters retain their BDB to their AC so long as they are aware of an attack or prepared for an unknown attack. This represents their stance and awareness of possible danger. Effectively, all a character needs to do to gain his BDB to AC is to declare the breakdown of his Combat Ability. If you have not then you are Off Guard.
- In a non-combat situation, maintaining combat readiness takes up a Combat Thread. If the character is doing anything else (such as talking with others, crafting an item, or any other task, those tasks also take up a Combat Thread. In order to maintain constant combat awareness, a character must make an additional Concentration check every half-hour (DC 12). Every subsequent half hour, the DC goes up by 2.
- Once combat starts, maintaining combat readiness no longer takes up an additional Combat Thread
Assigning Combat Ability points to the Counter Bonus allows characters to Counter opponents. The Counter Bonus represents a character's willingness to sacrifice a solid defense for a chance to render an attacker Open.
- In order to be able to Counter attacks, a character must have at least 1 point of Combat Ability assigned to the Counter Bonus.
Combat Ability points that are attributed to Combat Speed allow a character to attack faster. Points in Combat Speed serve as extra Action Points for attack actions (including trips).
Combat Ability can be advanced when a character levels up by spending Upgrade Points. Increasing a character's combat ability by 1 costs 8 points.