There are three ways to assemble Power Treads:
- ON will decrease the amount of relative damage taken
- OFF will increase the effectiveness of flat Health regeneration (e.g. Bottle, Salve, Ring of Health, Urn of Shadows, etc.)
- ON will decrease the amount of relative Mana spent
- OFF will increase the effectiveness of flat Mana regeneration (e.g. Bottle, Clarity, Ring of Basilius, etc.)
So in practice, turn on Strength treads when taking damage, Intelligence treads when casting spells, and Agility treads when regenerating using flat regeneration (such as Bottle which regenerates both Health and Mana at the same time). When attacking, switch to the Primary Attribute of your hero to increase damage output.