Rules of the Game
All About Movement (Part One)
By Skip Williams

For a game that's all about deeds of valor and daring, D&D has a vast number of rules that govern just how one gets from place to place. All in all, this is a good thing because it allows characters endless options for accomplishing things and it empowers DMs to build challenges that literally require players to think on their feet.

Alas, anything that makes the game more detailed and flexible also makes the game more complicated and inevitably raises questions that the rulebooks don't answer (at least not directly). Just what can you do while you're moving? How do you handle movement when it requires a skill check? What's the difference between having a swimming speed and making a Swim check? Read on to find the answers these questions and more.

This article focuses on tactical movement -- that is movement characters use during encounters. In Part One, we'll consider some basic definitions and other fundamentals of movement.

The Language of Movement

Here are a few terms you'll encounter in this article.

5-foot step: A small adjustment a creature makes to its position on the battlefield. Taking a 5-foot step takes no appreciable time, but a creature cannot take a 5-foot step in a round when it also moves.

Diagonal: Movement from one square to another through their corners. When measuring distances for movement, count the first diagonal (and all odd-numbered diagonals moved during the turn) as 5 feet and the second diagonal (and all even-numbered diagonals moved during the turn) as 10 feet.

Difficult Terrain: Terrain that hampers movement.

Encumbrance: A measure of how much a character's gear slows her down. A creature's encumbrance also can impose a cap on the amount of Dexterity bonus (if any) a creature can apply to its Armor Class and can impose a penalty on certain checks.

A character's armor or the total weight (see load) the character carries determines the character's degree of encumbrance. A character wearing armor is also carrying some weight, but you still use only one factor (armor or total weight) to determine encumbrance, and you take the worst effect.

Free Action: An action that takes no appreciable time at all. You can take as many free actions during your turn as your DM will allow, but you cannot take free actions during someone else's turn.

Hampered Movement: When conditions don't let you move as quickly as your speed would normally allow, your movement is hampered. When a creature enters a square where movement is hampered, it pays at least 10 feet of movement instead of the usual 5 feet. When moving diagonally into a square where movement is hampered, a creature pays at least 15 feet of movement.

Uneven surfaces, slippery surfaces, obstacles that leave you room to pass but require you to climb over them or detour around them, thick vegetation -- all these can hamper your movement.

A creature cannot charge, run, or take a 5-foot step when its movement is hampered.

Half Speed: Some conditions, such as blindness or entanglement, force a creature to move at half speed. A creature reduced to half speed always moves as though its movement is hampered. (Each square costs 10 feet of movement to enter, and each diagonal costs 15 feet.) Creatures reduced to half speed cannot charge, run, or take a 5-foot step.

Load: Load is a term for the total weight a creature carries. Load includes armor, weapons, gear, treasure, helpless comrades, and anything else the creature wears or carries.

Move: In the game's terms, a creature "moves" when it leaves one place and goes to another. During an encounter, a moving creature goes from one square on the battlefield to another.

Move Action: An action that (for game purposes) takes the same amount of time as moving your speed.

Normal Movement: This is not a standardized game term, but the rules (and this article) use it to indicate times when a creature uses a move action to move up to its speed -- as opposed to running, charging, or performing some other kind of special movement.

Obstacle: An object or barrier that hampers movement or blocks it completely. A wall, a pile of brush, or a fence is an obstacle.

Speed: A measure of how fast a creature can move across the battlefield or overland. In the D&D game, speeds are always given in number of feet, and they are always evenly divisible by 5 (because the basic unit of distance in the game is 5 feet).

A creature's speed rating before applying any enhancements (usually from magic or from a class feature) or reductions (usually from encumbrance or other impediments) is called its base speed.

A creature's speed rating after applying any enhancements is called its current speed.

Movement Basics

The basics of movement are covered on pages 146-150 in the Player's Handbook. Here's an overview:

  • A creature can use a move action to move its speed in combat once and still take a standard action. A creature can take a second move action instead of a standard action.
  • Encumbrance can reduce a creature's speed.
  • Bad visibility, difficult terrain, and obstacles can hamper movement. In addition, certain conditions that affect a creature can limit its speed.
  • Enemies block your movement (with some exceptions). You can move through (but not stop in) squares your allies occupy.
  • A creature cannot end its movement in a square that contains another creature (enemy or ally) unless that creature is helpless.

Moving

When you move across clear terrain, you "spend" 5 feet of movement to enter a square. If you're reduced to half speed or if poor visibility or difficult terrain hampers your movement, movement costs double.

Movement costs can double more than once. For example, if you're reduced to half speed and you try to enter a square with difficult terrain, the total movement cost is quadruple (20 feet of movement or 30 feet on the diagonal). This is an exception to the game's general rule for handling multipliers (see page 149 in the Player's Handbook).

An obstacle that doesn't block movement completely adds 10 feet to the cost of movement into its square. When such an obstacle is placed between two squares, you pay its movement cost when you cross the obstacle into the adjacent square -- treat the obstacle between squares as though it is in the square you're entering. Sometimes, it takes a skill check to cross an obstacle. For example, if you can't step over a wall, you'll need to make a Climb or a Jump check to cross it.

If you occupy more than one square, you pay the highest movement cost among all the squares you enter. So, if you're in two squares, and you would have to pay 10 to move from one square and pay 5 to move from another to where you want to go, you pay 10 since that's the highest movement cost possible.

Movement While Prone

When you're lying on the ground, you can move; however, you must crawl to do so. You crawl 5 feet as a move action that provokes an attack of opportunity.

Calculating Encumbrance

A creature's encumbrance can be light, medium, or heavy. As noted earlier, a creature's armor or load determines encumbrance.

The effect on encumbrance from armor is simply a matter of reading the armor's entry on Table 7-6 in the Player's Handbook to find out whether it's light, medium, or heavy.

A creature with light encumbrance suffers no reduction in speed.

A creature with medium encumbrance suffers a reduction of roughly one third of its base speed. These reduced speeds are shown on Table 8-3 in the Player's Handbook and on page 20 of the Dungeon Master's Guide.

A creature with heavy encumbrance suffers a reduction of roughly one third of its base speed, just as with medium encumbrance.

In addition, most kinds of armor impose a cap on the Dexterity bonus the wearer can use for Armor Class but not for other purposes such as initiative, Dexterity checks (but see below), and Reflex saving throws.

To determine encumbrance from weight carried, total up everything the creature carries. The creature's armor and shield (if any) are part of its load.

Compare the load with the creature's Strength score on Table 9-1 in the Player's Handbook to determine encumbrance from weight carried. The creature's size and number of feet can affect the load it can carry, as noted on page 162 of the Player's Handbook.

Medium or heavy encumbrance from a creature's load imposes its own Dexterity cap on Armor Class bonus and check penalty. These work exactly like the Dexterity cap and check penalty from wearing armor.

A creature uses the worst encumbrance effect (slowest speed, lowest Dexterity cap on Armor Class, highest check penalty) for its armor or its load. The rules work this way because no matter how strong a creature is, wearing most kinds of armor reduces its mobility at least somewhat.

What's Next?

Next week let's take a look at move actions.

About the Author

Skip Williams keeps busy with freelance projects for several different game companies and has been the Sage of Dragon Magazine since 1986. Skip is a co-designer of the D&D 3rd Edition game and the chief architect of the Monster Manual. When not devising swift and cruel deaths for player characters, Skip putters in his kitchen or garden (his borscht gets rave reviews).


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