How combat works
Combat is cyclical; everybody acts in turn in a regular cycle of rounds. Combat follows this sequence:
- When combat begins, all combatants roll initiative.
- Determine which characters are aware of their opponents. These characters can act during a surprise round. If all the characters are aware of their opponents, proceed with normal rounds. See the surprise section for more information.
- After the surprise round (if any), all combatants are ready to being the first normal round of combat.
- Combatants act in initiative order (highest to lowest).
- When everyone has had a turn, the next round begins with the combatant with the highest initiative, and steps 3 and 4 repeat until combat ends.
The Combat Round
Each round represents 6 seconds in the game world; there are 10 rounds in a minute of combat. A round normally allows each character involved in a combat situation to act.
Each round’s activity begins with the character with the highest initiative result and then proceeds in order. When a character’s turn comes up in the initiative sequence, that character performs his entire round’s worth of actions. (For exceptions, see Attacks of Opportunity and Special Initiative Actions.)
When the rules refer to a “full round”, they usually mean a span of time from a particular initiative count in one round to the same initiative count in the next round. Effects that last a certain number of rounds end just before the same initiative count that they began on.
At the start of a battle, each combatant makes a special Dexterity check called initiative check. A character's modifier to the initiative check is his Dexterity modifier plus any bonuses applicable to the initiative check. Characters act in order, counting down from the highest result to the lowest. In every round that follows, 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 act in order of total initiative modifier (highest first). If there is still a tie, the tied characters should roll to determine which one of them goes before the other. If the characters are allies, they can choose a sequence.
- At the start of a battle, a character is flat-footed until he has had a chance to act (specifically, before his first regular turn in the initiative order). A flat-footed character can’t use his Dexterity, dodge and shield bonuses to AC (if any), can’t make attacks of opportunity, nor can he use immediate actions.
- A character with the uncanny dodge extraordinary ability can never be caught flat-footed.
- Combat Reflexes: a character with this feat retains his Dexterity, dodge and shield bonuses to AC and can make attacks of opportunity even when he is flat-footed.
- Even if you can’t take actions, you retain your initiative score for the duration of the encounter.
When a combat starts, if you are not aware of your opponents and they are aware of you, you’re surprised.
Sometimes all the combatants on a side are aware of their opponents, sometimes none are, and sometimes only some of them are. Sometimes a few combatants on each side are aware and the other combatants on each side are unaware.
Determining awareness may call for Perception checks or other checks.
- The Surprise Round
- If some but not all of the combatants are aware of their opponents, a surprise round happens before regular rounds begin. In initiative order (highest to lowest), combatants who started the battle aware of their opponents each take a standard or move action during the surprise round. You can also take free actions during the surprise round. If no one or everyone is surprised, no surprise round occurs.
- Unaware Combatants
- Combatants who are unaware at the start of battle don’t get to act in the surprise round. Unaware combatants are flat-footed because they have not acted yet, so they lose any Dexterity, dodge and shield bonuses to AC.
This section summarizes the statistics that determine success in combat, then details how to use them.
An attack roll represents your attempt to strike your opponent on your turn in a round. When you make an attack roll, you roll a d20 and add your attack bonus. (Other modifiers may also apply to this roll.) If your result equals or exceeds the target’s Armor Class, you hit and deal damage. Automatic Misses and Hits: A natural 1 (the d20 comes up 1) on an attack roll is always a miss. A natural 20 (the d20 comes up 20) is always a hit. A natural 20 is also a threat—a possible critical hit (see the attack action).
Your attack bonus with a melee weapon is the following:
Base attack bonus + Strength modifier + size modifier.
If you use a light or finesse weapon made for a creature of your size category, you may use your Dexterity modifier instead of your Strength modifier on attack rolls.
With a ranged weapon, your attack bonus is the following:
Base attack bonus + Dexterity modifier + size modifier + range penalty
Your Armor Class (AC) represents how hard it is for opponents to land a solid, damaging blow on you. It’s the attack roll result that an opponent needs to achieve to hit you. Your AC is equal to the following:
10 + armor bonus + shield bonus + Dexterity modifier + other modifiers.
Note that armor limits your Dexterity bonus, so if you’re wearing armor, you might not be able to apply your whole Dexterity bonus to your AC (see Equipment).
Sometimes you can’t use your Dexterity bonus (if you have one). If you can’t react to a blow, you can’t use your Dexterity bonus to AC. If you don’t have a Dexterity bonus, your AC does not change.
- Other Modifiers
- Many other factors modify your AC.
- Dodge Bonuses
- Dodge bonuses represent actively avoiding blows. Any situation that denies you your Dexterity bonus also denies you dodge bonuses. (Wearing armor, however, does not limit these bonuses the way it limits a Dexterity bonus to AC.) Unlike most sorts of bonuses, dodge bonuses stack with each other.
- Deflection Bonus
- Magical deflection effects ward off attacks and improve your AC.
- Natural Armor
- If your race has a tough hide, scales, or thick skin you receive a bonus to your AC.
- Enhancement Bonuses
- Enhancement bonuses can apply to your armor or shield to increase the armor or shield bonus it provides. Enhancement bonuses can also apply to your natural armor to increase the natural armor bonus it provides.
- Size Modifier
- You receive a bonus or penalty to your AC based on your size. See Table 1 to the right.
- Touch Attacks
- Some attacks completely disregard armor, including shields and natural armor—the aggressor need only touch a foe for such an attack to take full effect. In these cases, the attacker makes a touch attack roll (either ranged or melee). When you are the target of a touch attack, your AC doesn’t include any armor bonus, shield bonus, or natural armor bonus. All other modifiers, such as your size modifier, Dexterity modifier, and deflection bonus (if any) apply normally. Some creatures have the ability to make incorporeal touch attacks. These attacks bypass solid objects, such as armor and shields, by passing through them. Incorporeal touch attacks work similarly to normal touch attacks except that they also ignore cover bonuses. Incorporeal touch attacks do not ignore armor bonuses granted by force effects, such as mage armor and bracers of armor.
If your attack succeeds, you deal damage. The type of weapon used determines the amount of damage you deal.
Damage reduces a target’s current hit points.
- Minimum Damage
- If penalties reduce the damage result to less than 1, a hit still deals 1 point of nonlethal damage.
- Strength Bonus
- When you hit with a melee or thrown weapon, including a sling, add your Strength modifier to the damage result. A Strength penalty, but not a bonus, applies on damage rolls made with a bow that is not a composite bow.
- Off-Hand Weapon
- When you deal damage with a weapon in your off hand, you add only half your Strength bonus. If you have a Strength penalty, the entire penalty applies.
- Wielding a Weapon Two-Handed
- When you deal damage with a weapon that you are wielding two-handed, you add 1-1/2 times your Strength bonus (Strength penalties are not multiplied). You don’t get this higher Strength bonus, however, when using a light weapon with two hands.
- Multiplying Damage
- Sometimes you multiply damage by some factor, such as on a critical hit. Roll the damage (with all modifiers) multiple times and total the results.
- Note: When you multiply damage more than once, each multiplier works off the original, unmultiplied damage. So if you are asked to double the damage twice, the end result is three times the normal damage.
- Exception: Extra damage dice over and above a weapon’s normal damage are never multiplied.
- Ability Damage
- Certain creatures and magical effects can cause temporary ability damage, or even permanent ability drain.
When your hit point total reaches 0, you’re disabled. When it reaches –1, you’re dying. When it gets to a negative amount equal to your Constitution score, you’re dead. See Injury and Death, for more information.
Attacks of Opportunity
Sometimes a combatant in a melee lets her guard down or takes a reckless action. In this case, combatants near her can take advantage of her lapse in defense to attack her for free. These free attacks are called attacks of opportunity. See the Attacks of Opportunity diagram for an example of how they work.
- Threatened Squares
- You threaten all squares into which you can make a melee attack. You threaten these squares even when it is not your turn. Generally, that means everything in all squares adjacent to your space (including diagonally). An enemy that takes certain actions while in a threatened square provokes an attack of opportunity from you. If you’re unarmed, you don’t normally threaten any squares and thus can’t make attacks of opportunity.
- Reach Weapons
- Most creatures of Medium or smaller size have a reach of only 5 feet. This means that they can make melee attacks only against creatures up to 5 feet (1 square) away. However, Small and Medium creatures wielding reach weapons threaten more squares than a typical creature. In addition, most creatures larger than Medium have a natural reach of 10 feet or more.
- Provoking an Attack of Opportunity
- Two kinds of actions can provoke attacks of opportunity: moving out of a threatened square and performing certain actions within a threatened square.
- Moving: Moving out of a threatened square usually provokes attacks of opportunity from threatening opponents. There are three common methods of avoiding such an attack—the 5-foot step, the withdraw action, and the Acrobatics skill.
- Performing a Distracting Act: Some actions, when performed in a threatened square, provoke attacks of opportunity as you divert your attention from the battle. Table 2: Actions in Combat notes many of the actions that provoke attacks of opportunity.
- Remember that even actions that normally provoke attacks of opportunity may have exceptions to this rule.
- Making an Attack of Opportunity
- An attack of opportunity is a single melee attack, and most characters can only make one per round. You don’t have to make an attack of opportunity if you don’t want to. You make your attack of opportunity at your normal attack bonus, even if you’ve already attacked in the round.
- An attack of opportunity “interrupts” the normal flow of actions in the round. If an attack of opportunity is provoked, immediately resolve the attack of opportunity, then continue with the next character’s turn (or complete the current turn, if the attack of opportunity was provoked in the midst of a character’s turn).
- Combat Reflexes and Additional Attacks of Opportunity: If you have the Combat Reflexes feat, you can add your Dexterity modifier to the number of attacks of opportunity you can make in a round. This feat does not let you make more than one attack for a given opportunity, but if the same opponent provokes two attacks of opportunity from you, you could make two separate attacks of opportunity (since each one represents a different opportunity). Moving out of more than one square threatened by the same opponent in the same round doesn’t count as more than one opportunity for that opponent. All these attacks are at your full normal attack bonus.
- Multiple Attacks of Opportunity
- If an action provokes attacks of opportunity from multiple opponents, resolve these in order of initiative.
Your speed tells you how far you can move in a round and still do something, such as attack or cast a spell. Your speed depends mostly on your size and your armor.
Humans, elves, half-elves, half-orcs, and most humanoid monsters have a speed of 30 feet (6 squares), or 20 feet (4 squares) in medium or heavy armor.
Dwarves, gnomes, and halflings have a speed of 20 feet (4 squares), or 15 feet (3 squares) when wearing medium or heavy armor (except for dwarves, who move 20 feet in any armor).
If you use two move actions in a round (sometimes called a “double move” action), you can move up to double your speed. If you spend the entire round running, you can move up to quadruple your speed (or triple if you are in heavy armor).
Generally, when you are subject to an unusual or magical attack, you get a saving throw to avoid or reduce the effect. Like an attack roll, a saving throw is a d20 roll plus a bonus based on your class and level (see Classes), and an associated ability score. Your saving throw modifier is: Base save bonus + ability modifier.
- Saving Throw Types
- The three different kinds of saving throws are Fortitude, Reflex, and Will:
- Fortitude: These saves measure your ability to stand up to physical punishment or attacks against your vitality and health. Apply your Constitution modifier to your Fortitude saving throws.
- 'Reflex: These saves test your ability to dodge area attacks and unexpected situations. Apply your Dexterity modifier to your Reflex saving throws.
- Will: These saves reflect your resistance to mental influence as well as many magical effects. Apply your Wisdom modifier to your Will saving throws.
- Saving Throw Difficulty Class
- The DC for a save is determined by the attack itself.
- Automatic Failures and Successes
- A natural 1 (the d20 comes up 1) on a saving throw is always a failure (and may cause damage to exposed items; see Items Surviving after a Saving Throw). A natural 20 (the d20 comes up 20) is always a success.