Movement

Why walk when you can run.

Default Movement Speeds
World of Warcraft includes two default movement speeds, which can be toggled using the NUM PAD "/" button:
 * 1) Run (7 yards per second) – Considered the default move speed as all characters are created set to this speed.
 * 2) Walk (2.5 yd/sec, 35.7% of run speed) – Confers no other in game effects, and hence only used for roleplaying or precision, such as positioning one's self without falling off a cliff. While walking is enabled, ground mounts and grounded flying mounts will move at walk speed too.

Mounts
Various movement increasing mounts are available, starting from level 20. To use a mount you will require the Riding Profession. The required riding profession corresponds to the quality of the mount:
 * Rare land based mounts require 75 (apprentice) riding.
 * Epic land based mounts require 150 (journeyman) riding.
 * Rare flying mounts require 225 (expert) riding.
 * Epic flying mounts require 300 (artisan) riding.

To mount up, you must right click on the mount item in your inventory. Using a mount has a 1.5 second cast time which can be interrupted as any other cast (eg by moving, or jumping). It will also be canceled if at any time during the cast you enter combat. Dismounting is instant and you return to Run/Walk mode.

Other Means of Increasing Movement Rate
Run and Mounted speeds can be increased using buffs, enchants, and items. See Movement speed effects for a complete list of means increase movement speed.

Decreasing Movement Rate
Run and Mounted speeds can be decreased by attacks and debuffs. See Movement speed effects for a complete list of means to decrease a target's movement speed.

Also, all mobs have a chance when attacking a player from behind to daze that player. This will apply a speed reduction debuff, and more importantly dismount the player if they are mounted.

Admeasurement
The speed can be measured by macros (for example with /run print(GetUnitSpeed("target") / 7 * 100); -command) and addons (for example with MonkeySpeed).