Resource

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 their resource. Resources are displayed just below the Hero's Health bar, both on the bottom-left of the screen by the Hero's portrait, and directly above the Hero's model.

Types of Resources

Mana

Main article: Mana

Most Heroes use Mana. It has a maximum of 500 at level 1, plus 10 per level up, to a maximum of 790 at level 30, except Probius, who has 600 Mana and gains no additional Mana per level. A Hero's Mana restores over time based on their Mana regen, and a Hero cannot use an Ability if they do not have enough Mana to fulfill its Mana cost. Mana regenerates constantly at a rate of 3 per second at level 1, plus 0.0976 per level up, to a maximum of 5.8304 per second at level 30. Heroes can also pick up Regeneration Globes that restore 7% of maximum Mana over 5 seconds.

Mana is used as a way to add another layer of depth to sustain. There is little counterplay to heroes that can poke at the enemy with no repercussions, but if they use their abilities too much they can run out of mana giving the opponent a chance to take advantage of their weakness. Sometimes it is best for heroes to hold onto their abilities for when you really need them so they don't go "out of mana" (OOM).

Unique Resources

Auriel	Auriel uses yellow Energy that can be consumed by her Basic Ability, Ray of Heaven, which converts all stored Energy to heal all allied Heroes in an area. Auriel's Energy is generated based on the damage dealt by her or the ally affected by her Trait Bestow Hope. The maximum Energy Auriel can store is 475, which scales by 4% per level. Talents can cause Ray of Heaven to only partially drain Energy, increase the max size of her Energy pool or improve her Energy generation. Her other Abilities do not use any Resources.
Chen	Chen uses yellow Brew that caps out at 100, and is consumed to use his Basic Abilities. It does not increase or decrease passively, and needs to be regenerated by using his Trait, which grants 50 Brew per second while channeling. Chen has a talent to remove the Brew cost of Flying Kick, and another that grants bonuses while at and either above or below 50 Brew.
Deathwing	Deathwing uses orange Energy that caps out at 100, and is consumed to use his Basic Abilities. Energy regenerates at the rate of 5 per second even while using abilities. Most of Deathwing's Energy is used to channel his powerful Molten Flame ability, which costs Energy to cast and maintain. Some talents reduce his Energy costs.
D.Va	D.Va uses pink Charge which is required to use Self-Destruct and Call Mech. In Mech Mode, D.Va gains 1% Charge every 2 seconds spent Basic Attacking and 25% for 100% Mech Health lost. Self-Destruct can be cast while at 100% Charge. In Pilot Mode, Charge instead tracks the cooldown of Call Mech, which takes 4 seconds if Self-Destruct was cast, or has a 45 second cooldown that can be lowered by 0.5 seconds per Basic Attack or 5 seconds per hero hit with Big Shot if D.Va's Mech was destroyed. D.Va has multiple talents that interact with Charge state and increase its generation. Her other Abilities do not use any resources.
Gazlowe	Gazlowe uses orange Scrap, which can only be used to summon his Rock-It! Turrets, consuming 4 Scrap. Gazlowe can hold up to 10 Scrap, regenerating 1 Scrap every 4 seconds, and can also pick it up from the ground when dropped by his destroyed Rock-It! Turrets. Talents can increase his Scrap total or grant him extra Scrap when hitting enemies with abilities. His other Abilities do not use any resources.
Junkrat	Junkrat uses orange Ammo that is only used by his Frag Launcher ability. He holds 4 ammo, and reloads all four at once after 12 seconds. The cooldown begins as soon as one grenade is launched. His Burst Fire talent reduces the Ammo cap to 3 and causes all grenades to be fired at once, and lowers the cooldown to 6 seconds. His other Abilities do not use any resources.
Lt. Morales	Lt. Morales uses yellow Energy that is spent by her Basic Ability Healing Beam, which constantly drains Energy to heal a target ally. Lt. Morales's Energy caps out at 100, and if she does not channel Healing Beam for 2 seconds it is regenerated at the rate of 6 per second. Talents can add an ability that drains energy to heal herself, or allow her to regenerate Energy through hitting enemies with attacks or abilities. Her other Abilities do not use any resources.
Sonya	Sonya uses orange Fury that is consumed to use most of her Basic Abilities. Fury has maximum of 100 and 6 Fury is generated from each Basic Attack and 2 Fury each time she takes damage. Sonya can also gain Fury by hitting enemies with Ancient Spear or through certain Talent selections.
Tracer	Tracer uses blue Ammo that is consumed by her Basic Attacks. Tracer's Ammo caps out at 10, and is automatically reloaded over 0.75 seconds when her clip is empty, she mounts, or she activates her trait. Her Abilities do not use any resources.
Valeera	Valeera uses yellow Energy that is consumed to use her Basic Abilities. Her Energy caps at 100 and regenerates at the rate of 10 per second. Valeera's Abilities have rather steep Energy costs and her Energy is consumed very rapidly, so many of her talents can grant increased Energy regen or refunds.

Non-Resource Bars

Fenix	Fenix uses white Shields which appear above his health bar and protect his health, and are not required to use his abilities, which have no cost. His maximum shield begins at 760, which scales by 4% per level. He regains 76 shield per second after not taking damage for 5 seconds. All shields Fenix receives will appear above his health instead of on top of it, and his personal shields always take damage last.
Hogger	Hogger uses red Rage that caps out at 100, but it is not required to use his abilities, which have no cost. Rage increases Hogger's cooldown speed by 1% per 2 Rage he has stored, and increases the damage of Hogg Wild by 1% per Rage. Talents can add extra benefits to Rage, like increased regen, movement speed, or attack speed. Rage is gained when Hogger lands Basic Attacks or takes damage, as well as when stunning enemies with Staggering Blow and landing a direct hit with Ez-Thro Dynamite. Rage begins to rapidly decay after leaving combat for 3 seconds. Hogger has many talents that help him generate Rage and interact with his Rage amount.
Zarya	Zarya uses purple Energy that caps out at 100, but it is not required to use her abilities, which have no cost. Each point of Energy increases all damage dealt by Zarya by 2%, meaning she can up to 200% bonus damage with abilities and Basic Attacks. Energy starts empty and is generated by absorbing damage with her Personal Barrier and Shield Ally abilities, at the rate of 1 energy for every 10 damage absorbed scaling with levels. After 0.5 seconds her Energy decays at the rate of 3 per second. She has many talents that interact with her Energy, whether it be by increasing the generation rate, granting special effects while at high energy, or allowing Energy to go above 100 by fulfilling certain requirements. She can also consume Energy as a resource with the talent Pain is Temporary.

No resource

There are a few heroes that do not use resources at all. These heroes are generally restricted by cooldowns or other features.

Abathur

Cho'gall

Illidan

The Lost Vikings

Murky

Samuro