Movement and Position

When using a grid to represent character's movement, the standard scale equates 1 inch (or a 1 inch square) to 5 feet in the game world.
Standard Scale
One inch (or one square) = 5 feet
"Next to" or "adjacent" = 1 inch (5 feet) away (or in adjacent square)
30mm figure = A human-size creature
A human-size creature occupies an area 1 inch (5 feet) across (or one square)
One round = 6 seconds
Tactical Movement
Where can a character move, how long it takes to get there, and whether he or she is vulnerable to attacks of opportunity while moving are key questions in combat.
How Far Can a Character Move?
Humans normally move 30 feet, although armor can slow a character down. Some creatures move faster or slower. A character's speed when unarmored is sometimes called base speed.
Encumbrance: A character encumbered by carrying a large amount of gear or a fallen comrade may move slower than normal.
Movement in Combat: Generally, a character can move his or her speed as a move action. If a character uses his or her attack action as a move action, the character can move again (for a total movement of up to twice the character's normal speed). If the character spends the entire round to run all out, he or she can move up to four times his or her normal speed. If a character does something that requires a full round, he or she can only take a 5-foot step.
Movement in Darkness: If a character moves when he or she can't see, such as in total darkness, his or her speed is limited to one-half normal. The Blind-Fight feat reduces this penalty.
Passing Through
Sometimes a character can pass through an area occupied by another character or creature.
Friendly Character: A character can move through a square occupied by a friendly character.
Unfriendly Character: There are two ways to move through a square occupied by a resisting enemy. The character can attempt an overrun. Or the character can attempt to tumble through a square occupied by an enemy (if the character has ranks in the Tumble skill; see the skill description).
A character can move through a square occupied by an unfriendly character who doesn't resist as if the character was friendly.
Square Occupied by Creature Three Sizes Larger or Smaller: Any creature can move through a square occupied by a creature three size categories larger or three categories smaller than it is.
Flanking
If a character is making a melee attack against an opponent, and an ally directly opposite the character is threatening the opponent, the character and his or her ally flank the opponent. The character gains a +2 bonus on his or her attack roll. The ally must be on the other side of the opponent so that the opponent is directly between the character and the ally.
A character doesn't gain a bonus for flanking when making a ranged attack.