Ability

In Heroes of the Storm, every Hero has their own diverse kit with unique abilities. A hero's ability kit is generally composed of 3 basic abilities useable right from level 1, a passive or active Trait, and a powerful Heroic ability. Abilities are used by pressing the corresponding abilities' hotkey, and may require a target whether it be a unit or the ground. All damaging abilities that do not modify a unit's Attack damage deal Spell damage; floating damage text will display Spell Damage as purple numbers above the target’s head. Damage, Healing and Shield values of abilities are subject to Scaling, while static values such as an abilities' duration or range are not.

Trait
All heroes have their own unique Trait (also known as a passive) that has a heavy impact on how that hero plays. Usually the Trait is a permanent effect that is always active, and is simply a descriptor for the unique mechanic the hero can utilize. Many heroes have an active Trait used by pressing the D hotkey, and work as an extra ability at no cost. Others have a passive Trait but can press the Trait's hotkey to disable a channeled ability, or through a Talent can activate the Trait for an effect.

Some heroes have two traits, such as Uther, Sylvanas, and Leoric. In these cases, the full effect of both traits can be found under the trait button, but separated by a title between the two effects.

Heroic
Most heroes have access to 2 special talent choices upon reaching level 10 that are exceptionally powerful abilities called Heroics (also known as an Ultimate). These Heroics are potentially game-changing abilities and are the strongest tools in a hero's arsenal, however Heroics are often limited by a long cooldown. A hero can only gain one heroic at a time and they will have wildly differing effects, so deciding which one to choose in different games is a big factor in playing well. At level 20 most heroes can upgrade their Heroic of choice by choosing a corresponding Storm Talent.

There are a few heroes that do not follow this convention. Chromie acquires her Heroic at level 8 due to her Trait, and likewise upgrades it at level 18. Tracer has one heroic, Pulse Bomb, that she gets automatically at level 1 and upgrades at level 10 as well as possibly at 20. Deathwing also only has one Heroic, Cataclysm, which is unlocked at level 1 and can possibly be upgraded at 10 and 20. Varian has a choice of 3 Heroics that greatly modify his stats, which are chosen at level 4. Alarak has the option of choosing the opposite Heroic choice at level 20 instead of upgrading. Maiev cannot upgrade her Heroics at level 20, instead having regular Storm Talents. Zeratul, Fenix, and Anduin do not have Storm Talents for Void Prison, Purification Salvo, and Lightbomb respectively, but still have options for their other Heroic.

Other
Many heroes can gain bonus abilities through Talents. These activate-able Talents are usually available on the 1 Hotkey, and if the hero can choose more than one they will fill up the other number Hotkeys from 2-6. These abilities often have rather long cooldowns essentially granting a bonus ability to supplement their kit. A few heroes have access to a bonus ability with no talents, including Zeratul's Vorpal Blade, Xul's Bone Armor, and Nova's Ghost Protocol.

Most heroes have all 3 of their basic abilities, but there are a few heroes who have a reduced number of ability choices. These heroes include The Lost Vikings who have no basic abilities and must unlock them through talents, Abathur who has only 2 basic abilities but gains a different kit while using Symbiote, D.Va's Pilot mode which has 2 active abilities and has 2 more abilities as talents, and Kharazim who doesn't have a Trait until one is chosen from 3 options at level 1.

Cooldown
Cooldown (or CD) is the minimum length of time that the player needs to wait after using an ability before they can use it again. Players can press ALT and left-click any of their Ability or Talent icons to quickly indicate their remaining Ability cooldown durations to teammates via chat messages. There are many ways to reduce the cooldown of a heroes' abilities.

Resources
Most heroes have a resource that limits how frequently they can use abilities, in addition to the cooldowns for individual abilities. A hero cannot use an ability without having the required amount of his or her resource. Resources are displayed just below the heroes' health bar, both on the bottom-left of the screen by the heroes' portrait, and directly above the heroes' model. Most heroes use Mana as a resource, but certain other heroes have their own unique resource or no resource at all.