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.

Damage

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.

Defense

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.

Speed

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.

Initiative

Every round, each combatant gets to do something. The combatants' initiative checks, from highest to lowest, determine the order in which they act, from first to last.

Initiative Checks

At the start of a battle, each combatant makes a single initiative check. An initiative check is a Dexterity check. Each character applies his or her Dexterity modifier to the roll, and anyone with the Improved Initiative feat gets an additional +4 bonus on the check. The GM finds out what order characters are acting in, counting down from highest result to lowest, and each character acts in turn. On all following rounds, the characters act in the same order (unless a character takes an action that results in his or her initiative changing; see Special Initiative Actions). If two or more combatants have the same initiative check result, the combatants who are tied go in order of total initiative modifier (including Dexterity modifier and Improved Initiative bonus, if applicable). If there is still a tie, roll a die.

Flat-Footed: At the start of a battle, before the character has had a chance to act (specifically, before the character's first turn in the initiative order), the character is flat-footed. A character can't use his or her Dexterity bonus to Defense while flat-footed.

Joining a Battle

If characters enter a battle after it has begun, they roll initiative at that time and act whenever their turn comes up in the existing order.

Surprise

When a combat starts, if a character was not aware of his or her enemies and they were aware of the character, that character is surprised. Likewise, a character can surprise his or her enemies if the character knows about them before they're aware of the character.

The Surprise Round

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 the 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 an attack action or move action during the surprise round (see Action Types, below). If no one or everyone is surprised, a surprise round does not occur.

Unaware Combatants

Combatants who are unaware at the start of battle do not get to act in the surprise round. Unaware combatants are still flat-footed because they have not acted yet. Because of this, they lose any Dexterity bonus to Defense.

Special Initiative Actions

Usually a character acts as soon as he or she can in combat, but sometimes a character wants to act later, at a better time, or in response to the actions of someone else.

Delay

By choosing to delay, the character takes no action and then acts normally at whatever point in the initiative count the character decides to act. When a character delays, he or she voluntarily reduces his or her own initiative result for the rest of the combat. When the character's new, lower initiative count comes up later in the same round, the character can act normally. The character can specify this new initiative result or just wait until some time later in the round and act then, thus fixing the character's new initiative count at that point.

A character cannot interrupt anyone's action with a delayed action (as a character can with a readied action; see below).

Delaying Limits
The longest a character can delay before taking an action is until after everyone else has acted in the round. At that point, the delaying character must act or else forfeit any action in that round.

If multiple characters are delaying, the one with the highest initiative modifier (or highest Dexterity, in case of a tie) has the advantage. If two or more delaying characters both want to act on the same initiative count, the one with the highest initiative modifier gets to go first. If two or more delaying characters are trying to go after one another, the one with the highest initiative modifier gets to go last; the others must go first or lose their action for the round.

Ready

The ready action lets a character prepare to take an action later, to interrupt another character. Essentially, the character splits his or her action, taking the move action on the character's initiative count and the attack action at a later point. On the character's turn, he or she prepares to take an action later, if a specific trigger is met. Then, later in the round, if the readied action is triggered, the character takes it, acting before the triggering action.

Readying does not provoke an attack of opportunity. (The character's move action, and the attack action he or she readies, may both provoke attacks of opportunity normally.)

Readying an Action
A character can ready an attack action or a move action. To do so, the character specifies the action he or she will take and the conditions under which the character will take it. Then, any time before the character's next action, the character may take the readied attack action in response to those conditions. The readied action occurs just before the event that triggers it. If the trigger is part of another character's actions, the readied action interrupts the other character. The other character continues his or her actions once the readied action is completed.

The character's initiative count changes. For the rest of the encounter, it is the count on which the character took the readied action, and the character acts immediately ahead of the character whose action triggered the readied action.

A character can take a 5-foot step as part of his or her readied action, but only if the character didn't otherwise move any distance during the round.

If the character comes to his or her next action and has not yet performed the readied action, the character doesn't get to take the readied action (though the character can ready the same action again). If the character takes his or her readied action in the next round, before his or her regular turn comes up, the character's initiative count rises to that new point in the order of battle, and he or she does not get your regular action that round.

Attacks of Opportunity

The melee combat rules assume that combatants are actively avoiding attacks. A player doesn't have to declare anything special for his or her character to be on the defensive. Sometimes, however, a combatant in a melee lets his or her guard down, and doesn't maintain a defensive posture as usual. In this case, combatants near him or her can take advantage of this lapse in defense to attack for free. These attacks are called attacks of opportunity.

Weapon Type

A character can use a melee weapon to make attacks of opportunity whenever the conditions for such an attack are met (see Provoking an Attack of Opportunity, below). In addition, a character can make attacks of opportunity with unarmed attacks if the character's unarmed attacks count as armed (see "Armed" Unarmed Attacks).

Threatened Squares

A character threatens the squares into which he or she can make a melee attack, even when it is not the character's action. Generally, that's all squares adjacent to the character's position. An enemy that takes certain actions while in a threatened square provokes an attack of opportunity from the character. A character can only make attacks of opportunity with melee weapons, never with ranged weapons.

Provoking an Attack of Opportunity

Two actions can provoke attacks of opportunity: moving out of a threatened square, and performing an action within a threatened square that distracts from defending and lets the character's guard down.

Moving out of a Threatened Square: When a character moves out of a threatened square, that character generally provokes an attack of opportunity. There are two important exceptions, however. A character doesn't provoke an attack of opportunity if all he or she moves is a 5-foot step, or if the character withdraws.

If the character doesn't start in a threatened square, but moves into one, the character has to stop there, or else he or she provokes an attack of opportunity as he or she leaves that square.

Performing an Action that Distracts the Character: Some actions, when performed in a threatened square, provoke attacks of opportunity because they make a character divert his or her attention from the fight at hand. Using a ranged weapon, in particular, provokes attacks of opportunity. Table: Actions in Combat notes many additional actions that provoke attacks of opportunity.

Making an Attack of Opportunity

An attack of opportunity is a single melee attack, and a character can only make one per round. A character does not have to make an attack of opportunity if he or she doesn't want to.

An experienced character gets additional regular melee attacks (by using the full attack action), but at a lower attack bonus. A character makes his or her attack of opportunity, however, at his or her normal attack bonus-even if the character has already attacked in this round.

When using a grid to represent character's movement, the standard scale equates 1 inch (or a 1 inch square) to 5 feet in the game world.

Standard Scale

One inch (or one square) = 5 feet

"Next to" or "adjacent" = 1 inch (5 feet) away (or in adjacent square)

30mm figure = A human-size creature

A human-size creature occupies an area 1 inch (5 feet) across (or one square)

One round = 6 seconds

Tactical Movement

Where can a character move, how long it takes to get there, and whether he or she is vulnerable to attacks of opportunity while moving are key questions in combat.

How Far Can a Character Move?

Humans normally move 30 feet, although armor can slow a character down. Some creatures move faster or slower. A character's speed when unarmored is sometimes called base speed.

Encumbrance: A character encumbered by carrying a large amount of gear or a fallen comrade may move slower than normal.

Movement in Combat: Generally, a character can move his or her speed as a move action. If a character uses his or her attack action as a move action, the character can move again (for a total movement of up to twice the character's normal speed). If the character spends the entire round to run all out, he or she can move up to four times his or her normal speed. If a character does something that requires a full round, he or she can only take a 5-foot step.

Movement in Darkness: If a character moves when he or she can't see, such as in total darkness, his or her speed is limited to one-half normal. The Blind-Fight feat reduces this penalty.

Passing Through

Sometimes a character can pass through an area occupied by another character or creature.

Friendly Character: A character can move through a square occupied by a friendly character.

Unfriendly Character: There are two ways to move through a square occupied by a resisting enemy. The character can attempt an overrun. Or the character can attempt to tumble through a square occupied by an enemy (if the character has ranks in the Tumble skill; see the skill description).

A character can move through a square occupied by an unfriendly character who doesn't resist as if the character was friendly.

Square Occupied by Creature Three Sizes Larger or Smaller: Any creature can move through a square occupied by a creature three size categories larger or three categories smaller than it is.

Flanking

If a character is making a melee attack against an opponent, and an ally directly opposite the character is threatening the opponent, the character and his or her ally flank the opponent. The character gains a +2 bonus on his or her attack roll. The ally must be on the other side of the opponent so that the opponent is directly between the character and the ally.

A character doesn't gain a bonus for flanking when making a ranged attack.