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.

Enhancement bonus
(does 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; as of Update 16 the listed amount is the actual bonus).
 * Speed X item effect (5% per X, max 30% at Speed VI)
 * Longstrider spell (listed and actual 15%)
 * Expeditious Retreat spell (listed and actual 25%)
 * Haste spell (listed 40% actual 32% run speed bonus, also 15% attack speed bonus)
 * Shadow Walk spell (unlisted but actual 40% run speed bonus, also 50% concealment)
 * House Phiarlan Favor Reward the Phiarlan Pendant of Time's Warp Time spell (unlisted but actual 50% speed bonus, only in public areas).
 * Lesser Pendant of Travel gives 20 charges of Warp Time spell (50% speed bonus in public areas).

Base increase
(stacks with each other and highest Enhancement bonus):
 * VIP characters move 10% faster in public spaces (since Update 15)
 * Fast Movement (barbarian) (verified 10% at Barbarian level 1)
 * Fast Movement (monk) (unverified +5% plus +5% per 3 levels of Monk: 10% at 3, 15% at 6, 20% at 9, 25% at 12, 30% at 15, 35% at 18).
 * Fast Movement (bard swashbuckler): +1% per bard level
 * Thief-Acrobat: Fast Movement +1% per rogue level.
 * Druid wild shape: Wolf (10%) or Winter Wolf (15%).
 * Feeding Frenzy: +1% per warlock level for 20 seconds after using Consume.

Action Boost bonus

 * Sprint Boost (action boost for various classes)
 * Swift Defense (Sacred Defender enhancements / Stalwart Defender enhancements)
 * Tactical Mobility (Battle Engineer enhancements)
 * Warchanter enhancements
 * Purple Dragon Knight enhancements

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
 * Gender
 * Strength, Constitution, or length of run time (you don't get Exhausted from running)

Reduced by

 * Carrying capacity: reduces speed when you are weighed-down:
 * Load: Light (0% to 33.33% load): no penalty.
 * Load: Medium (33.34% to 66.66% load): -4.3%.
 * Load: Heavy (66.67% to 100% load): -11.8%.
 * Load: Other (more than 100% load): -30.8%.
 * 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, Stunning, 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
 * Jumping
 * Flying (the spell cast by the Storm Reaver in The Reaver's Fate and Reaver's Refuge (Note that the Swim skill reportedly determines travel speed when flying. It does not affect speed when jumping/falling without Fly.))
 * Being harried due to being hit while high level Dungeon Alert is active

Tactical Consideration
For some players, run speed enhancements while in quests are not an advantage, as mobs correct to the speed of their target. More, diverse run speeds in a party primarily serve to spread out the party to the advantage of the NPCs.