Attack bonus

Every swing is one roll: d20 + your attack bonus, against the target's armour class. Beat it and you hit. A natural 20 always hits and a natural 1 always misses, whatever the numbers say.

Your attack bonus is built out of five parts, and they behave very differently from one another:

base attack bonus + ability modifier + the capped bonus + feats + the situation

The first two come from your class levels and your abilities. The third is the one with the famous +20 ceiling. The fourth ignores that ceiling entirely. The fifth you mostly never see.

Base attack bonus

Base attack bonus - BAB - comes from your class levels and nothing else. Strength, gear and spells have no part in it.

Every class follows one of three tracks:

The class list names the track for each class in its own column.

Past level 20 the class tables stop

This is the part that surprises people, and it is why two characters with the same class totals can have different attack bonuses.

The class tables are read only for the levels you took inside your first twenty character levels. After that, every character - fighter, wizard, anything - gains a flat +1 for every two character levels above 20, rounded up. At level 40 that is +10 for everyone.

So the highest base attack bonus a character can reach here is +30: twenty full-track levels taken early, plus the ten epic points.

The consequence is worth saying plainly: the order you take your levels in changes your attack bonus. A fighter 20 then wizard 20 has +20 from the tables and ends at +30. A wizard 20 then fighter 20 has +10 from the tables and ends at +20 - same classes, same totals, ten points apart. The build creator works this out as you plan, which is the main reason to plan a multiclass build there rather than in your head.

Saving throws follow the same shape with a different rounding, so they part company with your attack bonus across the epic levels.

The ability modifier

Melee uses your Strength modifier - unless you have Weapon Finesse and a higher Dexterity modifier, with a weapon light enough to qualify.

Ranged uses your Dexterity modifier - unless you have Zen Archery and a higher Wisdom modifier.

Two things on this server move that choice somewhere else:

• Divine Power substitutes Wisdom for whichever of Strength or Dexterity you would normally use on melee attacks, if Wisdom is higher. It adds nothing to damage.
• A warlock's pact weapon substitutes Charisma the same way, if Charisma is higher.

Both replace the modifier; they do not stack on top of it.

The capped bonus: +20, and narrower than it sounds

One part of your attack bonus is capped at +20, and it holds exactly two things:

• the higher of your weapon's attack bonus or its enhancement bonus - not the sum, the higher;
• bonuses from spells and spell-like abilities, including bard song and most feats you have to activate. Different spells stack with each other inside this pool.

Everything else stacks on top of the cap with no ceiling at all:

• always-on feats - Weapon Focus, Epic Weapon Focus, Epic Prowess;
• toggled stances such as Expertise;
• situational feats such as Bane of Enemies;
• feats spent on a single attack, such as Disarm.

This is why two characters in identical "+20 capped" gear can still land very differently. See caps and limits for the other ceilings in the same family.

Modifiers you never see on the sheet

These apply automatically when their conditions are met, and - the mounted penalty aside - none of them appears on your character sheet.

Flanking is negated by the target's Defensive Awareness, and the invisibility bonus by Blind Fighting.

Stances

Switching on a combat mode trades attack bonus for something else, and stays on until you switch it off.

Improved Power Attack costs half what it costs elsewhere. In standard Neverwinter Nights it is -10 to hit; here it is -5 for the same damage, which makes it strictly better than plain Power Attack once you have it.

Attacks per round, and why the later ones miss

A round is six seconds, and you get more than one swing in it. Each extra attack comes in 5 lower than the one before.

The number of attacks is frozen at what it was at character level 20. Epic levels raise every number in the sequence but never add a swing to it, so a level 40 fighter attacks at +30/+25/+20/+15 - four attacks, all ten points better.

A monk fighting unarmed or with a kama steps down by 3 instead of 5, and reaches six attacks where everyone else has four. That single difference is most of what makes an unarmed monk work.

Two things silently cut you to a single attack: a crossbow without Rapid Reload, and being slowed while not hasted.

Extra attacks

Beyond the main sequence there are two more:

• Free attacks - from haste, from feats, from attacks of opportunity. They step down by 5 even for a monk, and they ignore two-weapon penalties completely.
• Off-hand attacks - one for wielding two weapons, two with Improved Two-Weapon Fighting. They always step down by 5.

The order within a round is main attacks, then free attacks, then off-hand attacks.

Fighting with two weapons

Wielding a second weapon costs you attack bonus on both hands:

A shield or a torch in the off hand is not a weapon: it costs you nothing and grants no extra attack. A ranger in light or no armour is treated as having both Two-Weapon Fighting and Ambidexterity without spending the feats.

Reading it in game

The custom character sheet prints your full progression, main hand and off hand, with your stances and effects already folded in - the fastest honest answer to "what do I actually hit at". The plain number beside it is your base attack bonus on its own.