The first step to engaging in combat in this system is determining your base attack bonus (BAB).  Your BAB is dependent upon your class and level.  Furthermore, you receive an additional attack for every five points above one that you possess in your base attack bonus (ie, one attack at 1, another attack at 6, and so on).  The BAB values for these attacks are at five points less than the previous attack value.  Thus, a base attack bonus of 6 will allow a character to employ a second attack with a BAB of 1, a character with a BAB of 11 will be able to execute a second attack at a BAB of 6 and a third attack at a BAB of 1, and so forth.  Combat-oriented character classes such as barbarians and fighters progress in martial proficiency faster than others, giving them higher base attack scores than other classes at the same level.  Multi-class characters obtain their base attack scores by adding the BABs for all their classes.

Example:  Tom plays a tenth level half-orc barbarian, Grahk.  As a member of a martial class, Grahk received a one point increment to his BAB for each level he advanced.  Therefore, Grahk has a base attack bonus of +10/+5.  Melinda, on the other hand, plays a human fifth-level ranger/ fourth level-druid, Talishar.  To determine her total base attack bonus Melinda will need to first discover the BAB per each class of her character.  As a ranger, Talishar is a warrior-style character and receives the same per-level BAB adjustment as Grahk receives.  Thus, Talishar receives a base attack bonus of +5 for her ranger class.  However, druids are not combat-oriented characters and receive a different BAB advancement rate.  By checking the leveling chart for druids, Melinda learns that Talishar possesses a +3 base attack bonus for being a druid.  Melinda adds the two different BAB values for Talishar (5 + 3 = 8) to arrive at her character's final base attack bonus, +8/+3.

You should note that your character's actual combat values are more than merely his or her base attack bonus.  There are further modifiers to be applied first.  These adjustments are based upon your character's attributes and feats, as well as the weapon itself and combat conditions.  Strength and Dexterity scores will affect your character's efficiency with a given weapon, depending upon the type of weapon used.  In general, unless noted otherwise for the specific weapon, melee weapons apply Strength modifiers, while ranged weapons utilize Dexterity modifiers.  As noted, some feats can affect your actual attack rolls.  Such feats include Ambidexterity, Two Weapon Fighting, and Improved Two Weapon Fighting.  Magical weapons may have inherent bonuses or penalties that can affect combat performance.  Finally, certain conditions such as terrain, weather, and enemy proximity can affect your character's final attack values.

Example:  Grahk rushes into battle, swinging a +3 great axe at his enemy.  Checking Grahk's sheet, Tom sees that Grahk has an 18 Strength, giving him a +4 modifier.   The enchantments upon Grahk's great axe gives him a further +3 bonus.  Therefore, Grahk's attack score for his first swing is 17 (10 + 4 +3 = 17).  Talishar decides to fire upon the same target with whom Grahk has engaged into melee combat.  Talishar has a 16 Dexterity, granting her a +3 adjustment.  Normally she would receive a -4 penalty for firing into melee; however, she possesses the feat Precise Shot, which negates this penalty.  Talishar's bow receives no bonuses, but she does receive a +1 modifier for using +1 arrows.  Calculating in all her adjustments, Melinda realizes that Talishar's attack score is 12 (8 +3 + 1 = 12).

Once all these different factors have been taken into account you are prepared to roll the dice, adding the roll's value to your character's final attack value.  The resulting score is your actual atttack score.  If this score exceeds your enemy's adjusted armor class value then you have hit your target!

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