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. 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 movement provokes attacks of opportunity as normal (despite the distance covered, this move isn’t a 5-foot step).
Movement Modes Creatures may have modes of movement other than walking and running. These are natural, not magical, unless specifically noted.
Burrow A creature with a burrow speed can tunnel through dirt, but not through rock unless the descriptive text says otherwise. Creatures cannot charge or run while burrowing. Most burrowing creatures do not leave behind tunnels other creatures can use (either because the material they tunnel through fills in behind them or because they do not actually dislocate any material when burrowing see the individual creature descriptions for details.
Climb A creature with a climb speed has a +8 racial bonus on all Climb checks. The creature must make a Climb check to climb any wall or slope with a DC of more than 0, but it always can choose to take 10 even if rushed or threatened while climbing. The creature climbs at the given speed while climbing. If it chooses an accelerated climb it moves at double the given climb speed (or its base land speed, whichever is lower) and makes a single Climb check at a –5 penalty. Creatures cannot run while climbing. A creature retains its Dexterity bonus to Armor Class (if any) while climbing, and opponents get no special bonus on their attacks against a climbing creature.
Fly see also SRD:Fly A creature with a fly speed can move through the air at the indicated speed if carrying no more than a light load. (Note that medium armor does not necessarily constitute a medium load.) All fly speeds include a parenthetical note indicating maneuverability, as follows:
Perfect: The creature can perform almost any aerial maneuver it wishes. It moves through the air as well as a human moves over smooth ground. Good: The creature is very agile in the air (like a housefly or a hummingbird), but cannot change direction as readily as those with perfect maneuverability. Average: The creature can fly as adroitly as a small bird. Poor: The creature flies as well as a very large bird. Clumsy: The creature can barely maneuver at all. A creature that flies can make dive attacks. A dive attack works just like a charge, but the diving creature must move a minimum of 30 feet and descend at least 10 feet. It can make only claw or talon attacks, but these deal double damage. A creature can use the run action while flying, provided it flies in a straight line.
Swim A creature with a swim speed can move through water at its swim speed without making Swim checks. It has a +8 racial bonus on any Swim check to perform some special action or avoid a hazard. The creature can always can choose to take 10 on a Swim check, even if distracted or endangered. The creature can use the run action while swimming, provided it swims in a straight line.
Big and Little Creatures in Combat Creatures smaller than Small or larger than Medium have special rules relating to position.
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. A Tiny creature 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.
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.
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.