Characters are representations of people, creatures, and certain objects and mechanical creations within Hearthstone. A character may be a minion or a hero. Each character has an Attack and a Health attribute, and can attack other characters. If its Health reaches zero, the character is destroyed.
- Main article: Hero
Heroes represent the players or computer opponents in each battle. If a player's hero is destroyed, that player loses the game. There are 9 player hero classes, each with its own cards and Hero Powers. Certain cards can replace the player hero with another one during a battle; losing the original hero due to this process does not cause a game loss. Bosses have their own heroes, Powers, and cards as well.
Heroes come with 0 natural Attack value, but this can be increased by weapons and other cards and effects. Player standard heroes start with 30 Health, but other heroes such as bosses or replacement heroes may come with different amounts. In addition to Health, heroes may be protected by Armor.
- Main article: Minion
Minions are characters that are summoned onto the battlefield to fight for their hero, with a wide variety of statistics and abilities. Minions are controlled by the player who summoned them, and can be commanded to attack their opponent's minions, or even the opposing hero. Minions with Taunt can act as tanks, preventing the opponent's forces from attacking the hero directly with melee attacks until that minion is destroyed. Minions are a major element in battles between heroes, and are usually responsible for the majority of all damage dealt in a game.
- Main article: Attack
Each turn, any character with at least 1 Attack can choose to attack an enemy target of their choice. Even though Heroes have no Attack value by default, heroes can attack as well if they gain Attack by equipping weapons or using effects such as Shapeshift. Combat causes both the attacker and defender to simultaneously deal their Attack stat in damage to each other. If either character's Health reaches zero, they will be destroyed. Both participating characters can be simultaneously destroyed in this way.
Attacking exhausts a character, preventing it from attacking again until the next turn. Minions enter the battlefield in a state of exhaustion, unless they have the Charge ability. Other abilities affect attacking as well: Windfury allows a character to attack twice before becoming exhausted. Freeze effects can freeze a character in place, preventing them from attacking. Minions with Taunt must be attacked before other targets, although a player may choose which of several Taunt targets to attack. Some minions have attack restrictions stated in their card text. Finally, a multitude of triggered effects can occur when characters go into combat.