Intelligence

Intelligence (represented by the icon in-game) is the attribute that grants mana and mana regeneration. For each point of intelligence a hero has, their maximum mana increases by 13 and their mana regeneration increases by 0.04 mana per second.

Intelligence heroes gain attack damage based upon their intelligence.

Intelligence Heroes
Intelligence heroes have larger mana pools and regenerate mana faster than other heroes, which means heroes marked by this classification tend to focus on their abilities in combat. Intelligence heroes are almost all ranged heroes, with the only exceptions being Dark Seer and Ogre Magi. Because skills alone tend toward not scaling, heroes that have intelligence as their primary attribute as opposed to other attributes often do not build well statistically into the late game, although there are exceptions. They often fit into support and ganker roles. At the moment, there are Intelligence Heroes implemented in Defense of the Ancients, and  implemented in Dota 2.

Below is a table of all Heroes with intelligence as their primary attribute.