What resource do Dota 2 heroes spend to activate most abilities?

Dota 2 heroes spend mana points to activate most abilities.

Mana is the game’s primary resource for casting spells and abilities. When a hero uses an ability, the required number of mana points is deducted from the hero’s mana pool. Mana usually regenerates gradually, allowing abilities to be used again when the hero has enough resource and the ability’s cooldown has ended.

A hero’s attributes and items can affect its available mana and regeneration. Intelligence has traditionally been associated with mana, although Dota 2’s broader attribute system and item effects also influence how much a hero can cast. Some abilities have no mana cost, but most active abilities require mana.

Mana points are not the same as health points. Health measures survivability, while mana limits spell usage. Gold buys items, and experience increases levels; neither is normally spent when an ability is activated.