Abilities, also called spells, are unique skills that units can use. All heroes have one or more abilities that usually get stronger every time the hero levels up. Most abilities require mana to be used and once used they may also be placed on cooldown and can't be used again until their cooldown timer is up.
Most of the active abilities are cast as soon as the unit has enough mana for it and the ability isn't on cooldown.
Some abilities are cast on units: allies, enemies, self or a combination of those. If no unit is in range, the caster will walk towards the closest available target to cast on them.
Ground abilities are cast directly on the ground and can affect all units in that area.
Some abilities do not have a specific target and are used as soon as the unit has mana for it.
Passive abilities don't need to be cast, therefore they don't cost mana or go on cooldown, instead they require a certain action or condition to be effective.
Some different types of passive abilities:
- Luna's Moon Glaives and
- Slark's Essence Shift take effect when the hero attacks.
- Drow Ranger's Precision Aura only affects nearby allies.
- Puck's Phase Shift only activates when Puck is about to take damage.
Some abilities have preferred targets, while others are completely random. Examples:
- Pudge targets the farthest enemy from him when using Meat Hook.
- Sniper uses Assassinate on enemies with health lower than the damage from the ability.
- Techies tries to place Remote Mines next to the enemy he's attacking.
Most active ablilities require the casting unit to spend a certain amount of time before the spell's effects are applied. This time window is known as cast point or cast time. Only once the unit reaches this point does the spell take effect, goes on cooldown and its mana cost is spent. During the cast point, the unit can't perform any actions, if the unit is disabled or loses the mana required to cast the spell, it will be cancelled.
Cast point can vary heavily and is set for each spell individually.
Some abilities with long cast points are:
Keeper of the Light's Illuminate with 4.00 seconds
Sniper's Assassinate with 2.0 seconds.
Some abilities with short cast points are:
Arc Warden's Tempest Double with 0.15 seconds.
Venomancer's Venomous Gale with 0.16 seconds.
An active ability won't be cast if:
- The caster doesn't have enough mana for it.
- The ability is on cooldown.
- There are no valid targets.
- The caster is stunned or silenced.
- The ability can only be used under their specific conditions.
A passive ability won't have any effects while the unit is under the effect of break.