Abilities (also known as Spells or Skills) are unique skills that heroes, neutral creeps, and summons have access to, and can be seen along the central section of the HUD. All heroes have four abilities total, which includes three basic abilities and one ultimate ability. The ultimate is always the last ability furthest to the right. When leveled up, heroes gain skill points up to a maximum of 25. Each basic ability can level up 4 times, and an ultimate can be leveled up 3 times. The rest of the skill points go into their passive Talents. Each skill point put into an ability makes it more powerful.
Heroes can have any number of sub-abilities. Sub-abilities are tied to their parent ability and either automatically level up along with it or don't level up at all.
Time and Cost
All abilities have a cast time and cost, along with a cooldown.
Abilities use either the hero's cast time or its own unique cast time. The animation can be cancelled early to stop the ability from being used, and it will not spend Mana or go on cooldown if cancelled.
Instant Cast Time
Ignores cast time and activates instantly.
Will only provide its effect as long as the user does not get interrupted or cancel it early. Some forms of movement do not interrupt channeling.
The wait period after casting. The spell may not be allowed to be cast again until the cooldown time is over.
Mana Cost 
Requires Mana Points to be spent from your hero's mana pool. It cannot be cast without enough mana.
HP cost was previously known as HP removal. It directly subtracts the Hit Points of the user and does not count as damage or an attack. This allows effects that are stopped by on-hit triggers such as Bottle to continue working. HP cost is not considered a damage type, is always non-lethal, and cannot lower the user's HP below 1. The damage cannot be reduced or amplified by any ability. Below is a list of all spells with HP costs.
- Main Article: Charge Abilities
Charge based abilities use an ammo system rather than a basic single-use cooldown ability. Each charge recovers on a shared cooldown, allowing only 1 charge can be recharged at a time. Another charge does not recharge until the one before it has finished. Charge an be stored to allow multiple uses in quick succession. The maximum number of charges depends on the ability.
Some spells require a target to be cast, while other spells are released instantly.
Skills of this type do not require a target to be cast, and will activate when pressed. Skills of this type will start their effects as soon as their cast time or channel time has completed.
Skills of this type require a target to be selected to provide their effects. The cursor will change to allow target selection. If the spell has an area of effect, a blue visual indicator appears. The indicator has a central targeting visual to imply that it must be cast on a single target regardless of the area effect it provides after.
- Control Modifiers
- A few Consumables can be changed to Unit Targeting when the Control key is held. List is below:
|Bottle||Use Regenerate on an ally|
|Clarity||Use Clarity on an ally|
|Enchanted Mango||Use Enchanted Mango on an ally|
|Healing Salve||Use Healing Salve on an ally|
|Observer Ward||Transfer Ward to an ally|
|Sentry Ward||Transfer Ward to an ally|
Skills of this type require an area to be selected and may affect the area around the casting point. If the spell has an area of effect, a blue visual indicator appears to indicate the area that will be affected.
Active abilities must be used in order to apply their effects. Active abilities can consume mana, cooldowns, and usually have some method of targeting related to them. Most abilities are active abilities. Active abilities are indicated by a bevel around the icon, which makes them look like a pressable button. They can be activated by pressing their associated hotkey.
- Main Article: Channel
Channeled abilities require the user to stay still while it is active. A bar showing the duration of the channel time will appear when used. The effect ends if interrupted or cancelled. See the main article for a list of all channeled abilities and actives which can be used while channeling.
- Main Article: Passive
Passive abilities will apply their effects as long as they are learned. They can be applied to the hero itself, or as an aura belonging to the hero. Passive abilities do not consume mana and sometimes have cooldowns.
- Main Article: Toggle
Toggled abilities can change states between on and off. They are similar to passives but must be toggled to enable or disable their effects. Toggled abilities do not have cooldowns and sometimes consume mana.
- Main Article: Auto-Cast
Auto-Cast abilities are abilities that can be toggled on to automatically cast, or turned off to manually cast. An auto-castable ability will have an empty rim around it, which glows orange when toggled on. When toggled on the ability will apply when it can. For example, Drow Ranger's Frost Arrows will be used whenever she attacks a valid target. When attacking an invalid target such as a Tower, the Frost Arrows will not be used or consume mana, as if they are toggled off. These abilities can also be manually cast for greater precision, in which case they fire off a single time. If the ability is a Unique Attack Modifier it will be treated as a spell when manually cast, as opposed to a physical attack. This is known as Orb Walking. See here for a list of all auto-cast abilities.
An innate ability is a special ability that is not skilled and is already learned by the hero at the start of the game. This persists through all game modes, including Ability Draft. While their other skills may be shuffled around, a hero with an innate ability will still have their innate ability tied to them alone. All innate abilities are listed below:
|Earth Spirit||Stone Remnant|
Ultimate abilities are high impact abilities that may only be leveled 3 times instead of 4. They may be leveled at 6, 12, and 18 at the earliest. Some ultimates are affected by Aghanim's Scepter, a powerful item that passively upgrades them. If dropped or sold, the upgrade is lost until the hero is in possession of it again. Upgrades with irreversible effects will not allow Aghanim's Scepter to be removed from that hero's inventory. The upgrade Aghanim's Scepter provides is different for every hero. It can be a new ability entirely, an upgrade to the hero's basic abilities, or simply an increase in power to the hero's ultimate.