Movement speed or Run/Walk refers to the speed at which a character can run or walk, measured in yards per second, in Diablo II and Diablo III. In the first game, character movement speed is constant and same for the player and most creatures.
In Diablo I, players were forced to cover the large labyrinths of the Tristram Cathedral by walking. This was very time consuming and did not keep in pace with the fast-paced hack-and-slash nature of the game. Developers rectified this issue by introducing running into the sequel. This was also useful due to the change in sizes between the game, with Diablo II being much larger.
Like the real world, running continuously drains Stamina, a new Character attribute introduced to flesh out running. Walking does not drain Stamina, and even allows recovering it slowly. Standing idle allows regenerating Stamina very quickly.
Default walking speed is 4 y/s, running increases your speed by 2 y/s. The Paladin skill, Charge defaults to 9 y/s, but is not influenced by items that change Run/Walk speed. Running drains character's Stamina, making it impossible to run if depleted.
The limit on reduced speed for Run/Walk is 1 y/s, running speed is calculated by your theoretical walking speed, so it can fall below 3 y/s, but is also prevented from falling under 1 y/s. Note however, there is no lower limit on Charge, meaning you can charge in reverse if you are slowed below 0 y/s.
Though the speed at which the character runs does not depend on the Character Attributes, it can be modified by many factors. Certain magical items, mostly Boots, have magical attributes that increase Running Speed.
Items that provide a faster Run/Walk bonus come with diminishing returns, meaning that the higher it gets, the less of an increase you are gaining.
Skills modify your base speed (4 y/s) and provide their full listed effects without diminishing returns. Skills will also affect Charge speed.
Lastly, the Paladin can use the Vigor Aura to temporarily increase his speed. Similarly, the Barbarian uses the skill Increased Speed to permanently increase his speed, while Assassin has the Burst of Speed skill.
- Light armor has no negative influence on your speed. General rule is leather and lightweight metal armor and small or non-metal shields, as well as all Paladin Shields.
- Medium armor will decrease your Run/Walk by -0.2 y/s and Charge by -0.45 y/s. General rule is mail and light plate armor and large wooden and metal shields.
- Heavy armor will decrease your Run/Walk by -0.4 y/s and Charge by -0.9 y/s. General rule is heavier mail and plate armor and Tower Shield and its equivalents.
Some monsters like the Fallen also run. But they seem more likely to be fleeing. It is not known if they use a similar Stamina system or if they can run continuously. The Corrupted Rogues also run to close the distance between them and the player characters.
In Diablo III, movement speed is measured in percent, with 100% (initial normal speed) being roughly 6 yards per second (much like average real-life running speed), for both heroes and most monsters. Characters no longer have Stamina, cannot walk (always run), and movement speed penalties for gear are gone. Movement speed may not be brought below 20% by negative effects (remember that monsters build up CC resistance to it while slowed down).
One may gain a permanent speed increase from items, skills and from Paragon levels. Paragon points award 0.5% speed each (up to 25% total), and Boots may roll up to +12% speed. Some Legendary and Set Items may roll movement speed as well, but normally only boots do so. Most players prefer to gain speed by investing Paragon points, to avoid wasting affixes (as 50 points in Paragon stats award lesser amounts of attributes than an affix on a legendary or set item).
The permanent speed bonus is limited to +25%, which allows putting 50 Paragon points into the Core section and therefore freeing item affixes for more valuable stats. One of the few ways to gain a permanent speed over 25% is the Monk passive skill Fleet Footed.