Run speed

Run speed is the rate at which a character moves.

Run speed is the same for all races.

Barbarian and Monk classes get bonuses to run speed. All other classes have the same base run speed.

Modifiers of run speed:

Enhancement bonus (do not stack with each other):
 * Striding item effect which is commonly found on boots or rings (listed as 5%, 10%, 15%, 20%, 25%, or 30% speed bonus; actual bonus is 4%, 8%, 12%, 16%, 20%, 24%).
 * Longstrider spell (listed and actual 15%)
 * Expeditious Retreat spell (listed and actual 25%)
 * Thief-Acrobat: Showtime boost (listed but unverified 25% run speed bonus, and other skills bonus)
 * Haste spell (listed 40% actual 32% run speed bonus, plus 15% attack speed bonus)
 * Shadow Walk spell (listed but unverified 40% run speed bonus, plus 50% concealment)
 * House Phiarlan Favor Reward the Phiarlan Pendant of Time's Warp Time spell (listed and actual 50% speed bonus, only in public areas).

Base increase (stack with each other and highest Enhancement bonus):
 * Fast Movement (barbarian class feat) (verified 10% at Barbarian level 1)
 * Fast Movement (monk class feat) (unverified +5% per 3 levels of Monk: 5% at 3, 10% at 6, 15% at 9, 20% at 12, 25% at 15, 30% at 18).
 * Thief-Acrobat II (unverified 10% possible at Rogue level 12)
 * Barbarian Sprint Boost (verified 35-50% possible at Barbarian levels 1-10: 35% at 1, 40% at 4, 45% at 7, 50% at 10)
 * Ranger Sprint Boost (unverified 35-50%)

No change
 * Abundant step does not increase run speed, nor is the distance jumped increased with a higher run speed.
 * Type of armor worn.
 * Race
 * Sex
 * Strength, Constitution, or length of run time (you don't get Exhausted from running)

Reduced by:
 * Carrying capacity: reduces speed when you have Medium or Heavy Encumbrance, stops completely when Overloaded.
 * Some enhancements such as Stalwart Defender and Defender of Siberys Defensive Stances (1/2 or 1/3 speed), Monk's Mountain Stance
 * Some spells, such as Slow, Blindness, Ray of Exhaustion, Stinking Cloud, Sleep, etc.
 * Some Weapon enhancements, such as Crippling, Stench, Paralyzing, Strength Sapping, Tendon Slice, Weighted, Slowburst, Limb Chopper
 * Some melee special attacks, such as Hamstring, Sap, Stunning blow
 * Being fatigued after using the Barbarian Rage ability
 * Using the Sneak ability

Useful data from:
 * Help! I was robbed of my 30% striding! (part 87 of "Things don't work as advertised") thread
 * fastest mover thread
 * Striding/Monk Speed/Longstrider, do they stack? thread
 * Haste Types thread