Movement, Position, and Distance.

Few characters in a fight stand around motionless. Enemies appear
and charge the party. The heroes reply, advancing to take on new
foes after they down their first opponents. Wizards remain outside
the fight, looking for the best place to use their magic. Rogues
quietly skirt the fracas seeking a straggler or an unwary opponent to
strike with a sneak attack. Finally, if the fight is lost, most characters
seek to remove themselves from the vicinity. Movement is an
important element for gaining the upper hand on the battlefield.
Dungeons & Dragons miniatures are on the 30mm scale—a
miniature figure of a six-foot-tall human is approximately 30mm tall.
A square on the battle grid is 1 inch across, representing a 5-foot-by-
5-foot area.
TACTICAL MOVEMENT
Where you can move, how long it takes you to get there, and
whether you’re vulnerable to attacks of opportunity while you’re
moving are key questions in combat.
How Far Can Your Character Move?
Your speed is determined by your race and your armor (see Table 8–
3: Tactical Speed). Your speed while unarmored is your base land
speed.
Encumbrance: A character encumbered by carrying a large
amount of gear, treasure, or fallen comrades may move slower than
normal (see Carrying Capacity, page 161).
Hampered Movement: Difficult terrain, obstacles, or poor visibility
can hamper movement (see Terrain and Obstacles, below, and
Hampered Movement, page 163).
Movement in Combat: Generally, you can move your speed in a
round and still do something, such as swing an axe or cast a spell. If
you do nothing but move (that is, if you use both of your actions in a
round to move your speed), you can move double your speed. If you
spend the entire round running, you can move quadruple your
speed. If you do something that requires a full round you can only
take a 5-foot step.
Bonuses to Speed: A barbarian has a +10 foot bonus to his speed
(unless he’s wearing heavy armor). Experienced monks also have
higher speed (unless they’re wearing armor of any sort). In addition,
many spells and magic items can affect a character’s speed. Always
apply any modifiers to a character’s speed before adjusting the
character’s speed based on armor or encumbrance, and remember
that multiple bonuses of the same type to a character’s speed (such as
enhancement bonuses) don’t stack.
Table 8–3: Tactical Speed
No Armor or Medium or
Race Light Armor Heavy Armor
Human, elf, half-elf, half-orc 30 ft.(6 squares) 20 ft.(4 squares)
Dwarf 20 ft.(4 squares) 20 ft.(4 squares)
Halfling, gnome 20 ft.(4 squares) 15 ft.(3 squares)
Measuring Distance
Diagonals: When measuring distance, the first diagonal counts
as 1 square, the second counts as 2 squares, the third counts as 1, the
fourth as 2, and so on. (If it helps, you can think of a diagonal as a
distance of 1.5 squares.)
You can’t move diagonally past a corner (even by taking a 5-foot
step). You can move diagonally past a creature, even an opponent.
You can also move diagonally past other impassable obstacles, such
as pits.
Closest Creature: When it’s important to determine the closest
square or creature to a location, if two squares or creatures are
equally close, randomly determine which one counts as closest by
rolling a die.
Moving through a Square
Friend: You can move through a square occupied by a friendly
character, unless you are charging (page 154). When you move
through a square occupied by a friendly character, that character
doesn’t provide you with cover (see page 150).
obstacle even when helpless. In such cases, each square you move
through counts as 2 squares.)
Ending Your Movement: You can’t end your movement in the
same square as another creature unless it is helpless.
Overrun: During your movement or as part of a charge, you can
attempt to move through a square occupied by an opponent (see
Overrun, page 157).
Tumbling: A trained character can attempt to tumble through a
square occupied by an opponent (see the Tumble skill, page 84).
Very Small Creature: A Fine, Diminutive, or Tiny creature can
move into or through an occupied square. The creature provokes
attacks of opportunity when doing so.
Square Occupied by Creature Three Sizes Larger or Smaller:
Any creature can move through a square occupied by a creature
three size categories larger than it is. A gnome (Small), for example,
can run between the legs of a cloud giant (Huge).
A big creature can move through a square occupied by a creature
three size categories smaller than it is. A cloud giant, for example,
can step over a gnome.
Designated Exceptions: Some creatures break the above rules.
For example, a gelatinous cube fills the squares it occupies to a
height of 15 feet. A creature that completely fills the squares it
occupies cannot be moved past, even with the Tumble skill or
similar special abilities.
Terrain and Obstacles
The rules presented so far in this section assume that you’re moving
through an area clear of obstacles or difficult terrain. However, in
dungeons and wilderness areas, that’s often not the case.
Difficult Terrain: Difficult terrain, such as rubble, an uneven
cave floor, thick undergrowth, and the like, hampers movement.
Each square of difficult terrain counts as 2 squares of movement.
(Each diagonal move into a difficult terrain square counts as 3
squares.) You can’t run or charge across difficult terrain.
If you occupy squares with different kinds of terrain, you can
move only as fast as the most difficult terrain you occupy will allow.
(This is often significant for creatures whose space fills more than
one square, such as a giant.)
Flying and incorporeal creatures are not hampered by difficult
terrain.
Obstacles: Like difficult terrain, obstacles can hamper movement.
If an obstacle hampers movement but doesn’t completely
block it, such as a low wall or a deadfall of branches, each obstructed
square or obstacle between squares counts as 2 squares of movement.
You must pay this cost to cross the barrier, in addition to the
cost to move into the square on the other side. If you don’t have
sufficient movement to cross the barrier and move into the square
on the other side, you can’t cross the barrier. Some obstacles may
also require a skill check to cross (such as Climb of Jump).
On the other hand, some obstacles, such as floor-to-ceiling walls,
block movement entirely. A character can’t move through a
blocking obstacle.
Flying and incorporeal creatures can avoid most obstacles though
a floor-to-ceiling wall blocks a flying creature as well as a landbound
creature.
Squeezing: In some cases, you may have to squeeze into or
through an area that isn’t as wide as the space you take up. (This is
particularly true for creatures whose space fills more than one
square, such as a giant.) You can squeeze through or into a space that
is at least half as wide as your normal space. For instance, an ogre
(whose space is 10 feet, or 2 squares, wide) can squeeze through or
into a space at least 5 feet (1 square) wide. Each move into or
through a narrow space counts as if it were 2 squares, and while
squeezed in a narrow space you take a –4 penalty on attack rolls and
a –4 penalty to AC.
When a Large creature (which normally takes up four squares)
squeezes into a space that’s one square wide, the creature’s miniature
figure occupies two squares, centered on the line between the two
squares. For a bigger creature, center the creature likewise in the
area it squeezes into.
A creature can squeeze past an opponent while moving but it can’t
end its movement in an occupied square.
To squeeze through or into a space less than half your space’s
width, you must use the Escape Artist skill (page 73). You can’t
attack while using Escape Artist to squeeze through or into a narrow
space, you take a –4 penalty to AC, and you lose any Dexterity bonus
to AC.
Special Movement Rules
These rules cover special movement situations.
Accidentally Ending Movement in an Illegal Space: Sometimes
a character ends its movement while moving through a space
where it’s not allowed to stop. For example, you might incur an
attack of opportunity from a monk while moving through a friend’s
square and become stunned. When that happens, put your
miniature in the last legal position you occupied, or the closest legal
position, if there’s a legal position that’s closer.
Double Movement Cost: When your movement is hampered in
some way, your movement usually costs double. For example, each
square of movement through difficult terrain counts as 2 squares,
and each diagonal move through such terrain counts as 3 squares
(just as two diagonal moves normally do).
If movement cost is doubled twice, then each square counts as 4
squares (or as 6 squares if moving diagonally). If movement cost is
doubled three times, then each square counts as 8 squares (12 if
diagonal) and so on. This is an exception to the general rule that two
doublings are equivalent to a tripling.
Minimum Movement: Despite penalties to movement, you can
take a full-round action to move 5 feet (1 square) in any direction,
even diagonally. (This rule doesn’t allow you to move through impassable
terrain or to move when all movement is prohibited, such
as while paralyzed.) Such movement provokes attacks of opportunity
as normal (despite the distance covered, this move isn’t a 5-foot
step).
BIG AND LITTLE CREATURES IN COMBAT
Creatures smaller than Small or larger than Medium have special
rules relating to position. This section covers the basics; the
Dungeon Master’s Guide has more information on how to handle
exceptionally big or small creatures. The illustration on the following
page depicts creatures of various size categories.
Tiny, Diminutive, and Fine Creatures: Very small creatures
take up less than 1 square of space. This means that more than one
such creature can fit into a single square. For example, a Tiny creature
(such as a cat) typically occupies a space only 2-1/2 feet across,
so four can fit into a single square. Twenty-five Diminutive creatures
or 100 Fine creatures can fit into a single square.
Creatures that take up less than 1 square of space typically have a
natural reach of 0 feet, meaning they can’t reach into adjacent
squares. They must enter an opponent’s square to attack in melee.
This provokes an attack of opportunity from the opponent. You can
attack into your own square if you need to, so you can attack such
creatures normally. Since they have no natural reach, they do not
threaten the squares around them. You can move past them without
provoking attacks of opportunity. They also can’t flank an enemy.
Large, Huge, Gargantuan, and Colossal Creatures: Very large
creatures take up more than 1 square. For instance, an ogre (Large)
takes up a space 10 feet on a side (2 squares wide).
Creatures that take up more than 1 square typically have a natural
reach of 10 feet or more, meaning that they can reach targets even if
they aren’t in adjacent squares. For instance, an ogre can attack
targets up to 10 feet (2 squares) away from it in any direction, even
diagonally. (This is an exception to the rule that 2 squares of
diagonal distance is measured as 15 feet.)
Unlike when someone uses a reach weapon, a creature with
greater than normal natural reach (more than 5 feet) still threatens
squares adjacent to it. A creature with greater than normal
natural reach usually gets an attack of opportunity against
you if you approach it, because you must enter and move within the
range of its reach before you can attack it. (This attack of opportunity
is not provoked if you take a 5-foot step.)
Large or larger creatures using reach weapons can strike up to
double their natural reach but can’t strike at their natural reach or
less. For example, an ogre with a Large longspear could strike
with the longspear at opponents 15 or 20 feet away, but not at
those 5 or 10 feet away.