Niche D20A creature’s speed represents how far they can move with a single move action. Speed primarily is dependent on a creature’s race and armor; some classes or items may temporarily or permanently adjust a creature’s speed.
Moving is usually done through a move action; some actions, such as charging, may combine movement with another action. A creature may choose to take two move actions during their turn to move, or run as a full-round action.
Measuring Distance
In this system distance is measured assuming that 1 square is equal to 5 feet. Thus the terms 5 feet and 1 square may be used interchangeably with each other.
Diagonals
This system uses the “one two one” style of diagonal movement. This means when moving diagonally every other square counts as 2 squares of movement. As such the first diagonal counts as 1 square, second counts as 2, third counting as 1, and fourth as 2, etc.
A creature cannot make a diagonal movement past a corner, but may choose to move diagonally around an obstacle such as a pit.
Moving Through Occupied Squares
Creatures can move through squares occupied by an allied or friendly creature without having their movement impeded; with exception the charge action which cannot be impeded by allied or enemy creatures. You do not provoke attacks of opportunity from enemies when moving through an Ally’s square; you still provoke attacks of opportunity from the square you left as well as squares adjacent to the ally that are threatened by the enemy.
You cannot normally move through a square occupied by an enemy creature unless that creature is helpless. You cannot move into a space if drawing a line from any corner would pass through the space of an unwilling creature; as such a creature would be unable to take a 5 foot step to change which side of a creature they are currently on, or step between two creatures who are diagonally from each other. You can attempt to use acrobatics to move through a creature’s square, but this may be difficult depending on the creature (see acrobatics skill).
Creatures at least one size category larger than you present an obstacle to you even when helpless and as such are treated as difficult terrain to move through squares occupied by them.
If there is at least one size category difference in size between you and your opponent you may attempt to move into their square, but doing so provokes an attack of opportunity and cannot be done using a 5-foot step.
Difficult Terrain
Terrain that impedes a creature’s movement, such rocky terrain, steep stairs, and undergrowth. Each square of difficult terrain counts as 2 squares of movement, with each diagonal square movement counting as 3 squares of movement. Creatures cannot normally charge across difficult terrain.
When occupying squares with multiple kinds of terrain or difficult terrain, the effects do not stack, and instead a creature is only affected by the most difficult terrain occupied.
Creatures that that are using flight ignore the effects of difficult terrain on the ground even if they occupy the square of difficult terrain. Creatures climbing on walls next to, but not directly on the difficult terrain are treated the same, unless somehow the surface they are climbing on would also be considered difficult terrain. Incorporeal creatures are unaffected by difficult terrain.
Obstacles
Obstacles are usually objects such as a table, chair, waist-high wall, etc. that are in a path of movement, but can be easily stepped over/onto without needing to spend time climbing.
Obstacles can both occupy a square or simply be something that needs to be overcome to enter into the next square. Each obstructed square or space between squares that is obstructed counts as 2 squares of movement. If you run out of movement for your turn or simply do not possess enough speed using both move actions in a turn to cross over the obstruction to the square on the other side, your movement is instead immediately halted before the obstacle.
Some obstacles may simply represent hopping up onto a ledge, table, cart, or similar object where the obstacle is only the movement required to get onto the object or terrain, but once on top of the object movement is no longer hampered, unless it possesses some form of difficult terrain to hamper movement further.
Generally hopping off of an object, such as a table, does not present the same effort or challenge as getting onto it and as such is not treated as an obstacle.
If an object or terrain is too great of a challenge to pass normally, it may no longer count as a simple obstacle and may require a skill check (such as a climb or acrobatics check) to pass.
Similar to difficult terrain, flying creatures may simply fly over or around an obstacle provided there is enough space for them to pass through; while incorporeal creatures can usually ignore most obstacles.
Squeezing
Sometimes an area may not be as wide as the space you take up, and requires you to squeeze through. A creature can squeeze into a space that is at least half as wide as their normal space; with each square of squeezing counting as if it were 2 squares. While squeezing into a narrow space your movement and defenses are hampered, imparting a -4 penalty on attack rolls and AC.
A creature can attempt squeeze into a space less than half their space’s width, using the Escape Artist skill (see the Escape Artist skill), but doing so limits the creature’s movement, making them unable to make attacks, giving a -4 penalty to AC, and are Flat-Footed