How Combat Works
Combat in the D&D game is cyclical; everybody acts in turn in a regular cycle of rounds. Combat follows this sequence:
- Each combatant starts out flat-footed. Once a combatant acts, he or she is no longer flat-footed.
- The DM 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 of combat 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 one action (either a standard action or a move action) during the surprise round. Combatants who were unaware do not get to act in the surprise round. If no one or everyone starts the battle aware, there is no surprise round.
- Combatants who have not yet rolled initiative do so. All combatants are now ready to begin their first regular round of combat.
- Combatants act in initiative order (highest to lowest).
- When everyone has had a turn, the combatant with the highest initiative acts again, and steps 4 and 5 repeat until combat ends.
This section summarizes the statistics that determine success in combat, and 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 beats 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 Critical Hits sidebar).
Your attack bonus with a melee weapon is: Base attack bonus + Strength modifier + size modifier
With a ranged weapon, your attack bonus is: Base attack bonus + Dexterity modifier + size modifier + range penalty
Strength Modifier: Strength helps you swing a weapon harder and faster, so your Strength modifier applies to melee attack rolls.
Dexterity Modifier: Dexterity measures coordination and steadiness, so your Dexterity modifier applies to attacks with ranged weapons.
Size Modifier: The smaller you are, the bigger other creatures are relative to you. A human is a big target to a halfling, just as an ogre is a big target to a human. Since this same size modifier applies to Armor Class, two creatures of the same size strike each other normally, regardless of what size they actually are.
Range Penalty: The range penalty for a ranged weapon depends on the weapon and the distance to the target. All ranged weapons have a range increment, such as 10 feet for a thrown dart or 100 feet for a longbow (see Weapons). Any attack from a distance of less than one range increment is not penalized for range, so an arrow from a shortbow (range increment 60 feet) can strike at enemies up to 59 feet away with no penalty. However, each full range increment causes a cumulative -2 penalty on the attack roll. A shortbow archer firing at a target 200 feet away takes a -6 penalty on his attack roll (because 200 feet is at least three range increments but not four increments).
Thrown weapons, such as throwing axes, have a maximum range of five range increments. Projectile weapons, such as bows, can shoot up to ten increments.
When your attack succeeds, you deal damage. The type of weapon used (see Weapons) determines the amount of damage you deal. Effects that modify weapon damage apply to unarmed strikes and the natural physical attack forms of creatures.
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 damage.
Strength Bonus: When you hit with a melee or thrown weapon, including a sling, add your Strength modifier to damage result. A Strength penalty, but not a bonus, applies on attacks made with a bow that is not a composite bow.
Off-Hand Weapon: When you deal damage with a weapo your offhand, you add only 1/2 your Strength bonus.Wielding a Weapon Two-Handed: When you deal damage with a weapon that you are wielding two-handed, you add 1-1/2 time your Strength bonus. However, you don't get this higher Strength bonus when using a light weapon with two hands (see Light, One-Handed, and Two-Handed Melee Weapons, Weapons).
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 original, unmultiplied damage.
Exception: Extra damage dice over and above a weapon's normal damage, such as that dealt by a sneak attack or the special ability of a flaming sword, are never multiplied.
For example, Krusk the half-orc barbarian has a Strength bonus of +3. That means he gets a +3 bonus on damage rolls whenu a longsword, a +4 bonus on damage when using a greataxe (two-handed), and a +1 bonus on damage when using a weapon in his off hand. His critical multiplier with a greataxe is x3, so scores a critical hit with that weapon, he would roll 1dl2+4 points of damage three times (the same as rolling 3dl2+12).
Ability Damage: Certain creatures and magical effects cause temporary ability damage (a reduction to an ability score). The Dungeon Master's Guide has details on ability damage.
Your Armor Class (AC) represents how hard it is for opponent to land a solid, damaging blow on you. It's the attack roll result that an opponent needs to achieve to hit you. The average, unarmed peasant has an AC of 10. Your AC is equal to the following: 10 + armor bonus + shield bonus + Dexterity modifier + size modifier
Armor and Shield Bonuses: Your armor and shield each provide a bonus to your AC. This bonus represents their ability to protect you from blows.
Dexterity Modifier: If your Dexterity is high, you are adept at dodging blows. If your Dexterity is low, you are inept at it. That's why you apply your Dexterity modifier to your AC.
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 Armor and Shields).
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, nothing happens.) You lose your Dexterity bonus when, for example, an invisible opponent attacks you, you're hanging on to the face of a crumbling cliff high above a river of lava, or you're caught flat-footed at the beginning of a combat.
Size Modifier: The bigger a creature 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 halfling, for example, doesn't have a hard time hitting another halfling. See Size Modifiers.
Other Modifiers: Many other factors modify your AC.
Enhancement Bonuses: Enhancement effects make your armor better (+1 chainmail, +2 large shield, etc.).
Deflection Bonus: Magical deflection effects ward off attacks and improve your AC.
Natural Armor: Natural armor improves your AC. (Members of the common races don't have natural armor, which usually consists of scales, fur, or layers of huge muscles.)
Dodge Bonuses: Some other AC bonuses represent actively avoiding blows, such as the dwarf's AC bonus against giants or the AC bonus for fighting defensively. These bonuses are called dodge bonuses. 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. A dwarf's +4 dodge bonus against giants and his +2 dodge bonus for fighting defensively combine to give him a +6 bonus.
Touch Attacks: Some attacks disregard armor, including shields and natural armor. For example, a wizard's touch with a shocking grasp spell hurts you regardless of what armor you're wearing or how thick your skin happens to be. 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.
For example, if a sorcerer tries to touch Tordek with a shocking grasp spell, Tordek gets his +1 Dexterity bonus, but not his +4 armor bonus for his scale mail or his +2 shield bonus for his large wooden shield. His AC is only 11 against a touch attack.
Your hit points tell you how much punishment you can take before dropping. Your hit points are based on your class and level, and your Constitution modifier applies. Most monsters' hit points are based on their type, though some monsters have classes and levels, too. (Watch out for medusa sorcerers!)
When your hit point total reaches 0, you're disabled. When it reaches -1, you're dying. When it gets to -10, your problems are over - you're dead (see Injury and Death).
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 race and what armor you're wearing.
Dwarves, gnomes, and halflings have a speed of 20 feet, or 15 feet when wearing medium or heavy armor (except for dwarves, who move 20 feet in any armor).
Humans, elves, half-elves, and half-ores have a speed of 30 feet, or 20 feet in medium or heavy armor.
If you use two move actions in a round (sometimes called a "double move" action), you can move up to double your speeds. If you spend the entire round to run all out, you can move up to quadruple your speed (or triple if you are in heavy armor).
As an adventurer, you have more to worry about than taking damage. You also have to face the petrifying gaze of a medusa, a wyvern's lethal venom, and a harpy's captivating song. Luckily a tough adventurer can survive these threats, too.
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 level, and an ability score. Your saving throw modifier is: Base save bonus + ability modifier
Saving Throw Types: The three different kinds of savil 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. Fortitude saves can be made against attacks or effects such as poispon, disease, paralysis, petrification, energy drain, and disintegrate.
Reflex: These saves test your ability to dodge area attacks. Apply your Dexterity modifier to your Reflex saving throws. Reflex saves can be made against attacks or effects such as pit traps, catching on fire, fireball, lightning bolt, and red dragon breath.
Will: These saves reflect your resistance to mental influences as well as many magical effects. Apply your Wisdom modifier to your Will saving throws. Will saves can be made against attacks or effects such as charm person, hold person, and most illusion spells.
Saving Throw Difficulty Class: The DC for a save is determined by the attack itself. Two examples: A Medium monsrous centipede's poison allows a DC 11 Fortitude save. An ancient red dragon's fiery breath allows a DC 36 Reflex save.
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.
Every round, each combatant gets to do something. The combatants' initiative checks, from highest to lowest, determine the order in which they act.
Initiative Checks: At the start of a battle, each combatant makes an initiative check. An initiative check is a Dexterity check. Each character applies his or her Dexterity modifier to the roll. The DM finds out what order characters are acting in, counting down from highest result to lowest, and each character acts in turn. 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). Usually, the DM writes the names of the characters down in the initiative order so that on subsequent rounds he can move quickly from one character to the next. 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 again to determine which one of them goes before the other.
Monster Initiative: Typically, the DM makes a single initiative check for monsters and other opponents. That way each player gets a turn each round and the DM also gets one turn. At the DM's option, however, he can make separate initiative checks for different groups of monsters or even for individual creatures. For instance, the DM may make one initiative check lor an evil cleric of Nerull and another check for all seven of her zombie guards.
Flat-Footed: At the start of a battle, before you have had a chance to act (specifically, before your first regular turn in the initiative order), you are flat-footed. You can't use your Dexterity bonus to AC (if any) while flat-footed. (This fact can be very bad for you if you're attacked by rogues.) Barbarians and rogues have uncanny dodge extraordinary ability, which allows them to avoid losing their Dexterity bonus to AC due to being flat-footed. A flat-footed character can't make attacks of opportunity.
Inaction: Even if you can't take actions (for instance, if you become paralyzed or unconscious), you retain your initiative score for the duration of the encounter. For example, when paralyzed by a ghoul, you may miss one or more actions, but once the cleric casts remove paralysis on you, you may act again on your next turn.
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.
The DM determines who is aware of whom at the start of a battle. He may call for Listen checks, Spot checks, or other checks to see how aware the adventure are of are of their opponents. Some sample situations:
- The party (including Tordek, a fighter, and Jozan, a cleric, clanging along in metal armor) comes to a door in a dungeon. The DM knows that the displacer beasts beyond the door hear the party. Lidda listens at the door, hears guttural snarling, and warns the rest of the party. Tordek breaks the door open. Both sides are aware; neither is surprised. The characters and displacer beasts make initiative checks, and the battle begins.
- The party explores a ruined armory, looking through the rusted weapons for anything of value. Kobolds lurk in the nooks and crannies, waiting for the right time to strike. Jozan spots one of the kobolds, and the kobolds shriek and charge. The kobolds and Jozan each get a standard action during the surprise round. Kobolds that are close enough can charge adventurers and attack them. Others can move to try to put themselves in advantageous positions or shoot arrows at the flat-footed party members. Jozan can cast a spell, attack, or take some other action. After the surprise round, the first regular round begins.
- The party advances down a dark corridor, using light spells to see where they're going. At the end of the corridor, outside the range of the illumination, a kobold sorcerer doesn't want to be disturbed, and she angrily casts a lightning bolt. That's the surprise round. After the lightning bolt, the first regular round begins with the party in a tough spot, since they still can't see who attacked them.
The Surprise Round: If some but not all of the combatants are aware of their opponents, a surprise round happens before regular rounds begin. Any combatants 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 a standard action during the surprise round (see Standard Actions). You can also take free actions during the surprise round, at the DM's discretion. If 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 bonus to AC.
Special Initiative Actions
Here are ways to change when you act during combat by altering your place in the initiative order.
By choosing to delay, you take no action and then act normally on whatever initiative count you decide to act. When you delay, you voluntarily reduce your own initiative result for the rest of the combat. When your new, lower initiative count comes up later in the same round, you can act normally. You can specify this new initiative result or just wait until some time later in the round and act then, thus fixing your new initiative count at that point.
Delaying is useful if you need to see what your friends or opponents are going to do before deciding what to do yourself. The price you pay is lost initiative. You never get back the time you spend waiting to see what's going to happen. You can't, however, interrupt anyone else's action (as you can with a readied action).
Initiative Consequences of Delaying: Your initiative result becomes the count on which you took the delayed action. It you come to your next action and have not yet performed an action you don't get to take a delayed action (though you can delay again). If you take a delayed action in the next round, before your regular turn comes up, your initiative count rises to that new point in the order of battle, and you do not get your regular action that round.
The ready action lets you prepare to take an action later, after your turn is over but before your next one has begun. Readying is a standard action. It does not provoke an attack of opportunity (though the action that you ready might do so).
Readying an Action: You can ready a standard action, a move action, or a free action. To do so, specify the action you will take and the conditions under which you will take it. For example, you might specify that you will shoot an arrow at anyone coming through a nearby doorway. Then, any time before your next action, you may take the readied action in response to that condition, The action occurs just before the action that triggers it. If the triggered action is part of another character's activities, you interrupt the other character. Assuming he is still capable of doing so, he continues his actions once you complete your readied action.
Your initiative result changes. For the rest of the encounter your initiative result is the count on which you took the readied action, and you act immediately ahead of the character whose action triggered your readied action.
You can take a 5-foot step as part of your readied action, but only you don't otherwise move any distance during the round. For instance, if you move up to an open door and then ready an action to swing your sword at whatever comes near, you can't take a 5-foot step along with the readied action (since you've already moved in this round).
Initiative Consequences of Readying: Your initiative result becomes the count on which you took the readied action. If you come to your next action and have not yet performed your readies action, you don't get to take the readied action (though you ready the same action again). If you take your readied action in next round, before your regular turn comes up, your initiative count rises to that new point in the order of battle, and you do get your regular action that round.
Distracting Spellcasters: You can ready an attack against a caster with the trigger "if she starts casting a spell." If you damage the spellcaster, she may lose the spell she was trying to cast (as determined by her Concentration check result).
Readying to Counterspell: You may ready a counterspell against a spellcaster (often with the trigger "if she starts casting a spell"). In this case, when the spellcaster starts a spell, you get a chance to identify it with a Spellcraft check (DC 15 + spell level). If you do, an you can cast that same spell (are able to cast it and have it prepared, if you prepare spells), you can cast the spell as a counterspell and automatically ruin the other spellcaster's spell. Counterspelling works even if one spell is divine and the other arcane.
A spellcaster can usedispel magic to counters another spellcaster, but it doesn't always work.
Readying a Weapon against a Charge: You can ready certain piercing weapons, setting them to receive charges (see Weapons). A readied weapon of this type deals double damage if you score a hit with it against a charging character.
Attacks of Opportunity
The melee combat rules assume that combatants are actively avoiding attacks. A player doesn't have to declare anything special for her character to be on the defensive. Even if a character's miniature figure is just standing there on the battle grid, you can be sure that if some orc with a falchion attacks the character, she is weaving, dodging, and even threatening the orc with a weapon to keep the orc a little worried for his own hide.
Sometimes, however, a combatant in a melee lets her guard down. 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 diagram).
Threatened Squares: You threaten all squares into which you can make a melee attack, even when it is not your action. 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 (but see Unarmed Attacks).
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 away. However, Small and Medium creatures wielding reach weapons (such as a longspear) threaten more squares than a typical creature. For instance, a longspear-wielding human threatens all squares 10 feet away, even diagonally. (This is an exception to the rule that 2 squares of diagonal distance is measured as 15 feet.) In addition, most creatures larger than Medium have a natural reach of 10 feet or more; see Big and Little Creatures in Combat.
Provoking an Attack of Opportunity: Two kinds of actions can provoke attacks of opportunity: moving out of a threatened square and performing an action within a threatened square.
Moving: Moving out of a threatened square usually provokes an attack of opportunity from the threatening opponent. There are two common methods of avoiding such an attack — the 5-foot-step and the withdraw action).
Performing a Distracting Act: Some actions, when performed in a threatened square, provoke attacks of opportunity as you divert your attention from the battle. Casting a spell and attacking with a ranged weapon, for example, are distracting actions. 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. For instance, a character with the Improved Unarmed Strike feat doesn't incur an attack of opportunity for making an unarmed attack.
Making an Attack of Opportunity: An attack of opportunity is a single melee attack, and you can only make one per round. You don't have to make an attack of opportunity if you don't want to.
An experienced character gets additional regular melee attacks (by using the full attack action), but at a lower attack bonus. You make your attack of opportunity, however, 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 - such as by moving out of a threatened square and then casting a spell in a threatened square - 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.