Combat is played out in rounds, and in each round everybody acts in turn in a regular cycle. Combat usually runs in the following way.

  1. Each combatant starts the battle flat-footed. Once a combatant acts, he or she is no longer flat-footed.
  2. The GM determines which characters are aware of their opponents at the start of the battle. If some but not all of the combatants are aware of their opponents, a surprise round happens before regular rounds begin. The combatants who are aware of their opponents can act in the surprise round, so they roll for initiative. In initiative order (highest to lowest), combatants who started the battle aware of their opponents each take one move or attack action. Combatants who were unaware don't get to act in the surprise round. If no one or everyone starts the battle aware, there is no surprise round.
  3. Combatants who have not yet rolled initiative do so. All combatants are now ready to begin their first regular round.
  4. Combatants act in initiative order.
  5. When everyone has had a turn, the combatant with the highest initiative acts again, and steps 4 and 5 repeat until combat ends.

Combat Statistics

This section summarizes the fundamental combat statistics.

Attack Roll

An attack roll represents a character's attempts to strike an opponent on the character's turn in a round. When a character makes an attack roll, he or she rolls 1d20 and adds his or her attack bonus. If the result equals or beats the target's Defense, the character hits and deals damage. Many modifiers can affect the attack roll.

A natural 1 (the d20 comes up 1) on the attack roll is always a miss. A natural 20 (the d20 comes up 20) is always a hit. A natural 20 is also always a threat-a possible critical hit.

If the character is not proficient in the weapon he or she is attacking with (the character doesn't have the appropriate Weapon Proficiency feat), that character takes a -4 penalty on the attack roll.

Attack Bonus

A character's attack bonus with a melee weapon is:

Base attack bonus + Strength modifier + size modifier

With a ranged weapon, a character's attack bonus is:

Base attack bonus + Dexterity modifier + range penalty + size modifier

Strength Modifier

Strength helps a character swing a weapon harder and faster, so a character's Strength modifier applies to melee attack rolls.

Size Modifier

Creature size categories are defined differently from the size categories for weapons and other objects. Since this size modifier applies to Defense against a melee weapon attack or a ranged weapon attack, two creatures of the same size strike each other normally, regardless of what size they actually are. Creature sizes are compatible with vehicle sizes.

Table: Size Modifiers
Size (Example)Size Modifier
Colossal (blue whale [90 ft. long])-8
Gargantuan (gray whale [40 ft. long])-4
Huge (elephant)-2
Large (lion)-1
Medium-size (human)+0
Small (German shepherd)+1
Tiny (housecat)+2
Diminutive (rat)+4
Fine (horsefly)+8
Dexterity Modifier

Dexterity measures coordination and steadiness, so a character's Dexterity modifier applies when the character attacks with a ranged weapon.

Range Penalty

The range penalty for a ranged weapon depends on what weapon the character is using and how far away the target is. All ranged weapons and thrown weapons have a range increment (see Table: Ranged Weapons and Table: Melee Weapons). Any attack from a distance of less than one range increment is not penalized for range. However, each full range increment causes a cumulative -2 penalty on the attack roll. A thrown weapon has a maximum range of five range increments. Ranged weapons that fire projectiles can shoot up to ten increments.


When a character hits with a weapon, he or she deals damage according to the type of weapon. Effects that modify weapon damage also apply to unarmed strikes and the natural physical attack forms of creatures.

Damage is deducted from the target's current hit points.

Minimum Weapon Damage

If penalties to damage bring the damage result below 1, a hit still deals 1 point of damage.

Strength Bonus

When a character hits with a melee weapon or thrown weapon, add his or her Strength modifier to the damage.

Off-Hand Weapon: When a character deals damage with a weapon in his or her off hand, add only half of the character's Strength bonus.

Wielding a Weapon Two-Handed: When a character deals damage with a weapon that he or she is wielding two-handed, add 1.5 times the character's Strength bonus. However, the character doesn't get this higher Strength bonus when using a light weapon two-handed; in such a case, only the character's normal Strength bonus applies to the damage roll.

Multiplying Damage

Sometimes damage is multiplied by some factor. Roll the damage (with all modifiers) multiple times and total the results.

Bonus damage represented as extra dice is an exception. Do not multiply bonus damage dice when a character scores a critical hit.

Critical Hits

When a character makes an attack roll and gets a natural 20 (the d20 shows 20), the character hits regardless of the target's Defense, and the character has scored a threat of a critical hit. To find out if it is actually a critical hit, the character immediately makes another attack roll with all the same modifiers as the attack roll that scored the threat. If the second roll also results in a hit against the target's Defense, the attack is a critical hit. (The second roll just needs to hit to confirm a critical hit; the character doesn't need to roll a second 20.) If the second roll is a miss, then the attack just deals the damage of a regular hit.

A critical hit multiplies the character's damage. Unless otherwise specified, the multiplier is x2. (It is possible for some weapons to have higher multipliers, doing more damage on a critical hit.) Some weapons have expanded threat ranges, making a critical hit more likely. However, even with these weapons, only a 20 is an automatic hit. The Critical column on Table: Ranged Weapons and Table: Melee Weapons indicates the threat range for each weapon on the tables.

Bonus damage represented as extra dice is not multiplied when a character scores a critical hit.


A character's Defense represents how hard it is for opponents to land a solid, damaging blow on the character. It's the attack roll result that an opponent needs to achieve to hit the character. The average, unarmored civilian has a Defense of 10. A character's Defense is equal to:

10 + Dexterity modifier + class bonus + equipment bonus + size modifier

Dexterity Modifier

If a character's Dexterity is high, he or she is particularly adept at dodging blows or gunfire. If a character's Dexterity is low, he or she is particularly inept at it. Characters apply their Dexterity modifier to Defense.

Sometimes a character can't use his or her Dexterity bonus. If a character can't react to a blow, that character can't use his or her Dexterity bonus to Defense.

Class Bonus

A character's class and level grant the character an innate bonus to Defense. This bonus applies in all situations, even when the character is flat-footed or when the character would lose his or her Dexterity bonus for some other reason.

Equipment Bonus

If a character wears armor, it provides a bonus to his or her Defense. This bonus represents the armor's ability to protect the character from blows.

Armor provides a minimum bonus to anyone who wears it, but a character who is proficient in the use of a certain type of armor receives a larger bonus to Defense.

Sometimes a character can't use his or her equipment bonus to Defense. If an attack will damage the character just by touching him or her, that character can't add his or her equipment bonus (see Touch Attacks, below).

Size Modifier

The bigger an opponent is, the easier it is to hit in combat. The smaller it is, the harder it is to hit. Since this same modifier applies to attack rolls a creature doesn't have a hard time attacking another creature of the same size. Size modifiers are shown on Table: Size Modifiers.

Other Modifiers

Other factors can add to a character's Defense.

Feats: Some feats give a bonus to a character's Defense.

Natural Armor: Some creatures have natural armor, which usually consists of scales, fur, or layers of thick muscle.

Dodge Bonuses: Some other Defense bonuses represent actively avoiding blows. These bonuses are called dodge bonuses. Any situation that denies a character his or her Dexterity bonus also denies his or her dodge bonuses. Unlike most sorts of bonuses, dodge bonuses stack with each other.

Magical Effects: Some campaigns may include magic. Some magical effects offer enhancement bonuses to armor (making it more effective) or deflection bonuses that ward off attacks.

Touch Attacks

Some attacks disregard armor. In these cases, the attacker makes a touch attack roll (either a ranged touch attack roll or a melee touch attack roll). The attacker makes his or her attack roll as normal, but a character's Defense does not include any equipment bonus or armor bonus. All other modifiers, such as class bonus, Dexterity modifier, and size modifier, apply normally.

Hit Points

A character's hit points tell how much punishment he or she can take before dropping. Hit points are based on the character's class and level, and the character's Constitution modifier applies.

When a character's hit point total drops to 0, he or she is disabled. When it drops to -1, he or she is dying. When it drops to -10, the character is dead.


A character's speed tells how far he or she can move in a move action. Humans normally move 30 feet, but some creatures move faster or slower. Wearing armor can slow a character down.

A character normally moves as a move action, leaving an attack action to attack. The character can, however, use his or her attack action as a second move action. This could let the character move again, for a total movement of up to double his or her normal speed. Another option is to run all out (a full-round action). This lets the character move up to four times his or her normal speed, but a character can only run all out in a straight line, and doing so affects the character's Defense (see Run).

Saving Throws

Generally, when a character is subject to an unusual or magical attack, he or she gets a saving throw to avoid or reduce the effect. A saving throw is a 1d20 roll plus a bonus based on the character's class and level (the character's base save bonus) and an ability modifier.

A natural 1 (the d20 comes up 1) on a saving throw is always a failure. A natural 20 (the d20 comes up 20) is always a success.

A character's saving throw bonus is:

Base save bonus + ability modifier

The Difficulty Class for a save is determined by the attack itself.

Saving Throw Types

The three different kinds of saving throws are:

Fortitude: These saves measure a character's ability to stand up to massive physical punishment or attacks against his or her vitality and health such as poison and paralysis. Apply a character's Constitution modifier to his or her Fortitude saving throws.

Reflex: These saves test a character's ability to dodge massive attacks such as explosions or car wrecks. (Often, when damage is inevitable, a character gets to make a Reflex save to take only half damage.) Apply the character's Dexterity modifier to his or her Reflex saving throws.

Will: These saves reflect a character's resistance to mental influence and domination as well as to many magical effects. Apply the character's Wisdom modifier to his or her Will saving throws.