- Mana cost is the only attribute present on all types of cards, determining how much mana it costs to play that card
- Attack is present on all minion and weapon cards, determining how much damage they can deal
- Health and Armor serve to counter damage suffered, determining the survivability of minions and heroes
- Durability determines the number of times a weapon can be used before being destroyed
Attack and Health (or Durability for weapons) are commonly referred to as stats (statistics), and certain effects such as Darkspeaker can swap stats between cards. Stats are often presented numerically in the form Attack/Health, and minions are often referred to by their stats. For example a "2/3" is a minion with 2 Attack and 3 Health. Weapons can also be referred to by their stats; a "5/2 weapon" has 5 Attack and 2 Durability. The other attributes, Armor and mana cost, are not considered stats for game purposes, although some players consider mana cost to be a stat.
- For the act of attacking, see Attack.
Attack measures a character or weapon's capacity to deal damage, and is found on all minion and weapon cards. The current Attack value is shown in the bottom left, set against a single sword for heroes and minions, or a pair of crossed swords for weapons.
When characters engage in combat, they deal damage to each other equal to their Attack values. Characters with zero Attack (e.g., Shieldbearer, Nat Pagle, or many heroes) cannot be commanded to attack targets, but if their Attack attributes are increased, they immediately become able to attack.
Heroes by default have zero Attack, but can equip weapons and use abilities to grant them an Attack value. Equipping a weapon will automatically increase the hero's Attack by an amount equal to the weapon's Attack, but only during their own turn. Effects such as Heroic Strike, Demon Claws or Shapeshift can also increase a hero's Attack, but only temporarily, and only during their own turn. Since heroes have no Attack value on the opponent's turn, they usually deal no damage when attacked, and deal nearly all their damage when attacking. However, their Attack attribute will deal defensive damage if they are somehow attacked on their own turn.
Numerous effects can be used to alter a character's Attack value. Most increase the Attack, either permanently (e.g. Shattered Sun Cleric, Mark of the Wild) or temporarily (e.g. Dark Iron Dwarf, Savage Roar), while a few decrease Attack (e.g. Shrinkmeister) or set it to a specific value (e.g. Humility, Aldor Peacekeeper). If a character's Attack value would be reduced below 0, 0 is displayed and used instead. For example, using a Shrinkmeister's Battlecry on a Wrath of Air Totem will not result in any change to the Totem's Attack value, and if you then buff it with Abusive Sergeant's Battlecry the Totem's Attack will still be 0.
- For Wild format listings, see Attack/Wild format
|Name / Desc||Rarity||Type||Subtype||Class||Cost||Atk||HP||Description|
|Savagery||Rare||Spell||General||Druid||1||Deal damage equal to your hero's Attack to a minion.|
|Argent Braggart||Epic||Minion||General||PALADIN||2||1||1||Battlecry: Gain Attack and Health to match the highest in the battlefield.|
|Betrayal||Common||Spell||General||Rogue||2||Force an enemy minion to deal its damage to the minions next to it.|
|Crazed Alchemist||Rare||Minion||General||Any||2||2||2||Battlecry: Swap the Attack and Health of a minion.|
|Serena Bloodfeather||Legendary||Minion||General||Priest||2||1||1||Battlecry: Choose an enemy minion. Steal Attack and Health from it until this has more.|
|Shadow Word: Death||Common||Spell||Shadow||Priest||2||Destroy a minion with 5 or more Attack.|
|Augmented Porcupine||Epic||Minion||Beast||Hunter||3||2||4||Deathrattle: Deal this minion's Attack damage randomly split among all enemies.|
|Void Terror||Rare||Minion||Demon||Warlock||3||3||4||Battlecry: Destroy the minions on either side of this minion and gain their Attack and Health.|
|Big Game Hunter||Epic||Minion||General||Any||4||4||2||Battlecry: Destroy a minion with 7 or more Attack.|
Frenzy: Deal damage equal to this minion's Attack to all enemy minions.
Spellburst: Gain control of a random enemy minion with 2 or less Attack.
|Shadow Word: Ruin||Epic||Spell||Shadow||Priest||4||Destroy all minions with 5 or more Attack.|
|Steeldancer||Epic||Minion||General||4||4||4||Battlecry: Summon a random minion with Cost equal to your weapon's Attack.|
|Against All Odds||Epic||Spell||Holy||Priest||5||Destroy ALL odd-Attack minions.|
|Cutting Class||Common||Spell||General||5||Draw 2 cards.|
Costs (1) less per Attack of your weapon.
|Scrap Golem||Rare||Minion||Mech||Warrior||5||4||5||Taunt. Deathrattle: Gain Armor equal to this minion's Attack.|
|Mossy Horror||Epic||Minion||General||Any||6||2||7||Battlecry: Destroy all other minions with 2 or less Attack.|
|Ancient Void Hound||Epic||Minion||Demon||Demon Hunter||9||10||10||At the end of your turn, steal 1 Attack and Health from all enemy minions.|
|Showing all 18 cards|
- Main article: Health
Health, sometimes colloquially referred to as life, hit points or HP, is an attribute found on heroes and minions, reflecting the remaining survivability of the character. If a character's Health is reduced to 0 (or lower) that character will be destroyed. Health is displayed at the bottom right corner of each character's card or portrait, set against a red drop of blood.
Unlike other stats, Health has both a current and a maximum value. Taking damage will reduce the current Health value, while healing effects can increase the current value, up to the maximum; enchantments can also change the maximum Health value. Characters below maximum Health are considered "damaged", which can enable certain effects such as Enrage. Each character enters play at maximum Health.
- Main article: Armor
Armor is a form of secondary Health available only to heroes, gained through certain spells, Hero Powers and minions. Damage taken will always be deducted from Armor before Health. Only when a character has no armor or is reduced to 0 Armor will they lose Health from a damaging attack. Armor can effectively extend a hero's Health far beyond the 30 points otherwise allowed. Armor is only shown when present, in which case it is shown on the centre right of the hero, just above the Health icon, set against a silver, unbroken shield.
Durability is an attribute found only on weapons, although it is also displayed on heroes who have weapons equipped. It reflects the number of attacks the weapon is capable of making before it is used up. Each time a weapon is used to attack, it will lose one point of Durability. When a weapon reaches 0 Durability, it will be destroyed. Durability is shown in place of the Health stat, in the bottom right corner of the weapon display, on an icon depicting a rended shield.
Durability is only lost when the possessing hero directly attacks a target. Durability therefore is not lost if the possessing hero is attacked during the opponent's turn (since the weapon will not be used), and even in the few cases where it is possible for the hero to be attacked by a minion during their own turn (and the weapon does deal damage), Durability will still not be reduced. This prevents plays such as Misdirection from punitively sapping a weapon's Durability beyond the player's control.
Certain cards and effects can directly affect a weapon's Durability, such as the warrior spell Upgrade! and the Pirate minion Bloodsail Corsair's Battlecry, and some weapons such as Eaglehorn Bow and The Fist of Ra-den have such effects built-in. See below for a list.
|Name / Desc||Rarity||Type||Subtype||Class||Cost||Atk||HP||Description|
|Sphere of Sapience||Legendary||Weapon||Any||1||0||4||At the start of your turn, look at your top card. You can put it on the bottom and lose 1 Durability.|
|Headhunter's Hatchet||Common||Weapon||Hunter||2||2||2||Battlecry: If you control a Beast, gain +1 Durability.|
|Bulwark of Azzinoth||Legendary||Weapon||Warrior||3||1||4||Whenever your hero would take damage, this loses 1 Durability instead.|
Whenever this attacks, give your weapon +1/+1.
|Gorehowl||Epic||Weapon||Warrior||7||7||1||Attacking a minion costs 1 Attack instead of 1 Durability.|
|Showing all 5 cards|
- Main article: Mana cost
Mana cost determines how much mana is required to play a card from the hand, or use a Hero Power. The number is displayed inside a blue crystal in the upper left corner of each card, and at the top of each Hero Power. When a card is played or a Hero Power used, its mana cost is deducted from the player's supply of mana for that turn. Some effects can modify mana costs, although no mana cost can ever be less than zero.
While each stat is generally quite separate to and unaffected by the other stats, certain effects can allow them to directly influence or be exchanged for each other.
Stat numbers are able to climb as high as 10 digits, with Attack and Health values as high as 2,147,483,647 recorded in-game. Minions have been shown to "reset" to 0 Attack or Health upon exceeding 2 billion by a large enough margin. This is likely due to programming limits to stat sizes: integers are commonly stored with 32 bits, so exceeding 31 bits would cause the number to loop around to negative values. The highest possible Health has indeed been proven to be 231-1 (2,147,483,647), and it is suspected that other attributes have the same maximum. Assuming this is correct, negative Attack or Max Health appear to be displayed as simply 0. In the case of Attack, this hidden negative value can make the attribute appear "stuck" at 0 even when further buffs are applied, since the underlying number is actually far less than 0. Non-positive Health, on the other hand, simply results in the immediate death of the minion.
Aside from the maximum value, other anomalies have been found when Hearthstone does calculations with large stat values. These have been hypothesized to be due to floating-point arithmetic used during some effects, leading to lower precision and the somewhat inaccurate arithmetic that was observed, but also reduced vulnerability to the integer overflow described above.
- Patch 22.214.171.12444 (2014-03-11): A Water Elemental that damages a hero freezes that hero, even if it only damages armor.
- Previously: A Water Elemental which only damages armor will not freeze the hero.
- https://www.youtube.com/watch?v=VwwtzER5ewc Tested in Patch_126.96.36.19966 (Tavern Brawl patch)
- Shyug (2014-05-04). Hearthstone Max Damage 2 BILLION.
- Openarl (2014-03-17). 1.9 billion attack Leeroy Jenkins (Lorewalker Cho/Blessed Champion shenanigans).
- Wolfspeed (2014-06-05). Hearthstone: 1 Billion Lorewalker Cho Fail.