Attack sequence

When a character attacks another player a number of calculations are made to determine how successful that attack was. The following is from the perspective of the attacker:

Attacker's swing
A d20 is rolled to produce a number between 1 and 20. This will be refer to as Die A.
 * Add the attack bonus (AB) of the character
 * The initial AB is based on the character's base attack bonus
 * Characters with multiple attacks per round get lower AB for each subsequent attack in the sequence.
 * Add the following:
 * ability modifier depending on the type of attacks.
 * strength modifier if using a melee weapon.
 * If the character has the weapon finesse feat, is using a light or otherwise appropriate melee weapon and has a greater dexterity modifier than strength modifier, add dexterity modifier instead of strength.
 * dexterity modifier if using a ranged weapon.
 * size modifier
 * +1 if using a weapon the character has the weapon focus feat for.
 * - 4 if using a weapon the character is not proficient in.
 * deduct the character's armor check penalty if wearing armor the character is not proficient in.

The final value is known as the character's attack roll.

Defender's armor
To calculate the armor class (AC) of the defender.
 * The base AC value is 10. Add the following:
 * Armor bonus. From armor worn, this does not stack with itself.
 * Shield bonus. From a held shield, this does not stack with itself.
 * Dexterity modifier. This cannot exceed the maximum dexterity bonus of the currently worn armor.
 * Size modifier. Smaller things are harder to hit.


 * Deflection bonus. Usually gained from magic items, this does not stack with itself.
 * Natural armor bonus. Armor-like skin and toughness, this does not stack with itself.
 * Dodge bonus. This is the ability of a character to evade the attack. It stacks with itself.

Touch attacks
The defender's armor bonus, shield bonus, and natural armor bonus (including any enhancement bonuses to those values) do not apply to AC against a touch attack.

Flat-footed
When a defender is attacked while unaware, or incapable of protecting themselves, they are considered flat-footed. The defender's dexterity modifier and dodge do not count towards AC. Uncanny dodge allows the dexterity modifier to be retained.

The impact
If the character's attack roll exceeds the defender's AC, the character has been succesful.

Automatic results
If the character's attack roll dice (die A) is a natural 20 then the attack has automatically succeded irrelevant of the actual modifiers.

If die A is a natural 1 then the attack has automatically failed irrelevant of the actual modifiers.

Damage
The amount of damage done to the defender after when successfully attacked is:

The damage-dice is dependant on the weapon used with the following modifiers:
 * Melee or thrown weapons add strength modifier, however:
 * Off-hand weapons only add &frac12; strength.
 * Two-handed weapons (except light weapons) add 1&frac12; strength.

Minimum damage
The modified damage roll is considered to be at least 1 even if the actual modified value was lower.

Critical hit
If a character's successful attack roll dice (Die A) was within the critical threat range of the weapon he was using this can mean a critical hit has been scored. A second d20 attack roll is made, including the same modifiers. If this also exceeds the defender's AC then the attack is a critical hit. If the dice roll was a miss, then the attack is still a normal hit.

Critical hits mean additional damage rolls equal to the weapon's critical multiplier.

Multiplying damage
When multiplying damage, the damage is additional rolls of the weapon damage roll with the same modifiers. All multiplication is derived from the original damage roll dice.

e.g.

A d6 damage roll which has scored a critical hit of &times;2 is the same as 2d6. If the same dice recieves an additional &times;3 the total damage will be 5d6 (2d6 + 3d6) not 6d6.

Additional damage
Additional damage rolls from other sources (e.g. sneak attack) are not affected by damage multiplications.

e.g.

A d8 damage roll which has scored a critical hit of &times;2 is the same as 2d8. If the same dice recieves an additional +d6 from a sneak attack, the damage becomes 2d8+d6 not 2d8+2d6.

Damage reduction
If the defender has damage reduction it is possible that the final damage value can be reduced to 0.