Combat Modifiers

Sometimes you just have to go toe-to-toe in a fight, but you can
usually gain some advantage by seeking a better position, either
offensively or defensively. This section covers the rules for when
you can line up a particularly good attack or are forced to make a
disadvantageous one.
FAVORABLE AND
UNFAVORABLE CONDITIONS
Depending on the situation, you may gain bonuses or take penalties
on your attack roll. Generally, any situational modifier created by
the attacker’s position or tactics applies to the attack roll, while any
situational modifier created by the defender’s position, state, or
tactics applies to the defender’s AC. Your DM judges what bonuses
and penalties apply, using Table 8–5: Attack Roll Modifiers and
Table 8–6: Armor Class Modifiers as guides.
COVER
One of the best defenses available is cover. By
taking cover behind a tree, a wall, the side of a
wagon, or the battlements of a castle, you can
protect yourself from attacks, especially ranged
attacks, and also from being spotted.
To determine whether your target has
cover from your ranged attack, choose a
corner of your square. If any line from
this corner to any corner of the target’s
square passes through a square or border
that blocks line of effect or provides
cover, or through a square occupied by a
creature, the target has cover (+4 to
AC).
Table 8–5: Attack Roll Modifiers
Attacker is . . . Melee Ranged
Dazzled –1 –1
Entangled –21 –21
Flanking defender +2 —
Invisible +22 +22
On higher ground +1 +0
Prone –4 —3
Shaken or frightened –2 –2
Squeezing through a space –4 –4
1 An entangled character also takes a –4 penalty to Dexterity, which may
affect his attack roll.
2 The defender loses any Dexterity bonus to AC. This bonus doesn’t
apply if the target is blinded.
3 Most ranged weapons can’t be used while the attacker is prone, but
you can use a crossbow or shuriken while prone at no penalty.
When making a melee attack against an adjacent target, your
target has cover if any line from your square to the target’s square
goes through a wall (including a low wall). When making a melee
attack against a target that isn’t adjacent to you (such as with a reach
weapon), use the rules for determining cover from ranged attacks.
Low Obstacles and Cover: A low obstacle (such as a wall no
higher than half your height) provides cover, but only to creatures
within 30 feet (6 squares) of it. The attacker can ignore the cover if
he’s closer to the obstacle than his target.
Cover and Attacks of Opportunity: You can’t execute an attack
of opportunity against an opponent with cover relative to you.
Cover and Reflex Saves: Cover grants you a +2 bonus on Reflex
saves against attacks that originate or burst out from a point on the
other side of the cover from you, such as a red dragon’s breath
weapon or a lightning bolt. Note that spread effects (see page 175),
such as a fireball, can extend around corners and thus negate this
cover bonus.
Cover and Hide Checks: You can use cover to make a Hide
check. Without cover, you usually need concealment (see below) to
make a Hide check.
Table 8–6: Armor Class Modifiers
Defender is . . . Melee Ranged
Behind cover +4 +4
Blinded –21 –21
Concealed or invisible — See Concealment —
Cowering –21 –21
Entangled +02 +02
Flat-footed +01 +01
(such as surprised, balancing, climbing)
Grappling (but attacker is not) +01 +01, 3
Helpless –44 +04
(such as paralyzed, sleeping, or bound)
Kneeling or sitting –2 +2
Pinned –44 +04
Prone –4 +4
Squeezing through a space –4 –4
Stunned –21 –21
1 The defender loses any Dexterity bonus to AC.
2 An entangled character takes a –4 penalty to Dexterity.
3 Roll randomly to see which grappling combatant you strike. That
defender loses any Dexterity bonus to AC.
4 Treat the defender’s Dexterity as 0 (–5 modifier). Rogues can sneak
attack helpless or pinned defenders. See also Helpless Defenders,
page 153.
Soft Cover: Creatures, even your enemies, can provide you with
cover against ranged attacks, giving you a +4 bonus to AC. However,
such soft cover provides no bonus on Reflex saves, nor does soft
cover allow you to make a Hide check.
Big Creatures and Cover: Any creature with a space larger than
5 feet (1 square) determines cover against melee attacks slightly
differently than smaller creatures do. Such a creature can choose any
square that it occupies to determine if an opponent has cover against
its melee attacks. Similarly, when making a melee attack against
such a creature, you can pick any of the squares it occupies to
determine if it has cover against you.
Total Cover: If you don’t have line of effect to your target (for
instance, if he is completely behind a high wall), he is considered to
have total cover from you. You can’t make an attack against a target
that has total cover.
Varying Degrees of Cover: In some cases, cover may provide a
greater bonus to AC and Reflex saves. For instance, a character
peering around a corner or through an arrow slit has even better
cover than a character standing behind a low wall or an obstacle. In
such situations, the DM can double the normal cover bonuses to AC
and Reflex saves (to +8 and +4, respectively). A creature with this
improved cover effectively gains improved evasion against any
attack to which the Reflex save bonus applies (see the improved
evasion ability in the rogue class description, page 51). Furthermore,
improved cover provides a +10 bonus on Hide checks.
The DM may impose other penalties or restrictions to attacks
depending on the details of the cover. For example, to strike effectively
through a narrow opening, you need to use a long piercing
weapon, such as an arrow or a spear. A battleaxe or a pick just isn’t
going to get through an arrow slit.
CONCEALMENT
Besides cover, another way to avoid attacks is to make it hard for
opponents to know where you are. Concealment encompasses all
circumstances where nothing physically blocks a blow or shot but
where something interferes with an attacker’s accuracy.
Concealment gives the subject of a successful attack a chance that
the attacker missed because of the concealment.
Typically, concealment is provided by fog, smoke, a shadowy area,
darkness, tall grass, foliage, or magical effects that make it difficult to
pinpoint a target’s location.
To determine whether your target has concealment from your
ranged attack, choose a corner of your square. If any line from this
corner to any corner of the target’s square passes through a square or
border that provides concealment, the target has concealment.
When making a melee attack against an adjacent target, your
target has concealment if his space is entirely within an effect that
grants concealment (such as a cloud of smoke). When making a
melee attack against a target that isn’t adjacent to you (for instance,
with a reach weapon), use the rules for determining concealment
from ranged attacks.
In addition, some magical effects (such as the blur and displacement
spells) provide concealment against all attacks, regardless of
whether any intervening concealment exists.
Concealment Miss Chance: Concealment gives the subject of a
successful attack a 20% chance that the attacker missed because of
the concealment. If the attacker hits, the defender must make a miss
chance percentile roll to avoid being struck. (To expedite play, make
both rolls at the same time). Multiple concealment conditions (such
as a defender in a dog and under the effect of a blur spell) do not
stack.
Concealment and Hide Checks: You can use concealment to
make a Hide check. Without concealment, you usually need cover
to make a Hide check.
Total Concealment: If you have line of effect to a target but not
line of sight (for instance, if he is in total darkness or invisible, or if
you’re blinded), he is considered to have total concealment from
you. You can’t attack an opponent that has total concealment,
though you can attack into a square that you think he occupies. A
successful attack into a square occupied by an enemy with total
concealment has a 50% miss chance (instead of the normal 20% miss
chance for an opponent with concealment).
You can’t execute an attack of opportunity against an opponent
with total concealment, even if you know what square or squares the
opponent occupies.
Ignoring Concealment: Concealment isn’t always effective. For
instance, a shadowy area or darkness doesn’t provide any concealment
against an opponent with darkvision. Remember also that
characters with low-light vision can see clearly for a greater distance
with the same light source than other characters. A torch, for
example, lets an elf see clearly for 40 feet in all directions from the
torch, while a human can see clearly for only 20 feet with the same
light. (Fog, smoke, foliage, and other visual obstructions work normally
against characters with darkvision or low-light vision.)
Although invisibility provides total concealment, sighted opponents
may still make Spot checks to notice the location of an invisible
character. An invisible character gains a +20 bonus on Hide
checks if moving, or a +40 bonus on Hide checks when not moving
(even though opponents can’t see you, they might be able to figure
out where you are from other visual clues).
Varying Degrees of Concealment: As with cover, it’s usually
not worth differentiating between more degrees of concealment
than described above. However, the DM may rule that certain situations
provide more or less than typical concealment, and modify
the miss chance accordingly. For instance, a light fog might only
provide a 10% miss chance, while near-total darkness could provide a
40% miss chance (and a +10 circumstance bonus on Hide checks).
FLANKING
When making a melee attack, you get a +2 flanking bonus if your
opponent is threatened by a character or creature friendly to you on
the opponent’s opposite border or opposite corner.
When in doubt about whether two friendly characters flank an
opponent in the middle, trace an imaginary line between the two
friendly characters’ centers. If the line passes through opposite
borders of the opponent’s space (including corners of those borders),
then the opponent is flanked.
Exception: If a flanker takes up more than 1 square, it gets the
flanking bonus if any square it occupies counts for flanking.
Only a creature or character that threatens the defender can help
an attacker get a flanking bonus.
Creatures with a reach of 0 feet can’t flank an opponent.
HELPLESS DEFENDERS
A helpless opponent is someone who is bound, sleeping, paralyzed,
unconscious, or otherwise at your mercy.
Regular Attack: A helpless character takes a –4 penalty to AC
against melee attacks, but no penalty to AC against ranged attacks. A
helpless defender can’t use any Dexterity bonus to AC. In fact, his
Dexterity score is treated as if it were 0 and his Dexterity modifier to
AC as if it were –5 (and a rogue can sneak attack him).
Coup de Grace: As a full-round action, you can use a melee
weapon to deliver a coup de grace to a helpless opponent. You can
also use a bow or crossbow, provided you are adjacent to the target.
You automatically hit and score a critical hit. If the defender survives
the damage, he must make a Fortitude save (DC 10 + damage
dealt) or die. A rogue also gets her extra sneak attack damage against
a helpless opponent when delivering a coup de grace.
Delivering a coup de grace provokes attacks of opportunity from
threatening opponents because it involves focused concentration
and methodical action on the part of the attacker.
You can’t deliver a coup de grace against a creature that is immune
to critical hits, such as a golem. You can deliver a coup de
grace against a creature with total concealment, but doing this
requires two consecutive full-round actions (one to “find” the creature
once you’ve determined what square it’s in, and one to deliver
the coup de grace).