While every collectible card game is composed of a wide variety of effects, many choose to categorize these for the sake of simplicity and memorability. Oftentimes, with Hearthstone as no exception, this means developing keywords. Keywords denote particular card effects, usually ones that lack complexity and that are easily understood. However, the downside of keywords is a higher barrier to entry. Establishing too many of them can confuse new players. Now, they not only have to keep track of all nine classes, but they also have to take time to learn each keyword. The user interface solves this problem fairly well by describing each keyword when it is moused over. Nevertheless, outlining them individually and providing examples of cards with these effects might be helpful to newer players.
Battlecry is the most prominent keyword out there. It describes an effect that activates when a card is played from the hand. This means that a minion summoned from the deck would not qualify. More confusingly, the Battlecry effect of a minion summoned from the hand through some other effect (Alarm-o-Bot or Voidcaller, for instance) would not activate. This is because “play” refers to manually taking a minion from the hand and placing it on the battlefield. Abusive Sergeant, Antique Healbot, Defender of Argus, Azure Drake, and Big Game Hunter are some of the most popular and recognizable Battlecry cards. Their value tends to come from the fact that the effect is immediate. One should note that Battlecry effects aren’t restricted to minions; Glaivezooka, for instance, is a weapon with Battlecry. Like many other keywords, Battlecry has its share of related cards. For example, Nerub’ar Weblord increases the cost of minions with Battlecry, discouraging their use. On the other hand, Brann Bronzebeard synergizes with them, doubling Battlecry effects. Keep in mind, however, that not all Battlecry effects are positive. Brann Bronzebeard plus Flame Imp, dealing six damage to oneself, is not what one would call a good combo!
Taunt is another common keyword, second only to Battlecry in frequency. Taunt shakes up the Hearthstone battle system by restricting potential attack targets. Generally, the attacking player can target any enemy minion, or the enemy hero, with each attack. However, a minion with Taunt forces the opponent to choose it as a target. This is used to protect one’s other minions or the hero, forcing the opponent to make suboptimal attacks. Thus, Taunt minions are especially valuable against aggressive decks and those specializing in minion combat. The keyword has an interesting functionality with Stealth. Without a special exception, combining Taunt (only this minion may be attacked) with Stealth (Stealth will be considered soon in greater detail, but it basically prevents the enemy from targeting the minion until it attacks or deals damage) would form a lock, where the opponent could not attack at all. In this case, a Stealth minion is not awarded Taunt until after it is “revealed.” Keep in mind that Taunt only affects minion attacks; it does not prohibit a player from targeting a different minion or the hero with any other sort of effect. Also, if there is more than one Taunt minion in play, any of them may be attacked. Popular Taunt cards include Sludge Belcher, Druid of the Claw, and Tirion Fordring. The Warrior class has several related cards, including Bolster, Sparring Partner, and King’s Defender, and The Black Knight is versatile anti-synergy, using a Battlecry effect to destroy Taunt minions.
Deathrattle is the next most popular keyword. Popularized in The Curse of Naxxramas adventure (and notably absent from the Basic Set of cards), Deathrattle effects activate when the accompanying card is destroyed. Since Deathrattles activate upon destruction, unless the minions are Silenced or Transformed first, they are often difficult to avoid. Many Deathrattle minions like Haunted Creeper and Sludge Belcher are described as “sticky,” meaning it is difficult to completely remove the minion. Thus, Deathrattle minions like Nerubian Egg are valuable against “area of effect” cards that indiscriminately damage multiple targets because their effects still activate, leaving more cards behind. Of course, not all Deathrattle effects summon more minions. Like Battlecry, Deathrattle can also appear on weapons, such as Death’s Bite and Charged Hammer. Another similarity is the potential for negative effects, such as those found on Zombie Chow and Darnassus Aspirant. Like many other keywords, spells can give other cards Deathrattle, but they don’t possess it themselves. Some of the more popular Deathrattle cards are Mad Scientist, Deathlord, and Sylvanas Windrunner. There are related cards for the keyword, such as Baron Rivendare and Undertaker, but some, such as Scarlet Purifier, discourage their use.
Like Taunt, Charge is a keyword that alters Hearthstone’s standard combat system. Generally, minions enter the Battlefield in a state of exhaustion, preventing them for attacking until the next turn. This is a mechanic borrowed from Magic: the Gathering, which was originally known as “summoning sickness.” Charge is also a carry-over, based on “haste” in MTG, which allows creatures to ignore summoning sickness and attack, as well as use tap or untap abilities, the same turn they are played. In Hearthstone, there is no concept of “tapping,” but Charge still allows minions to attack on the turn they enter the battlefield. This offers greater offensive flexibility, since Charge minions can force better trades in minion combat than what might usually be possible and deal damage directly to the opponent. For the latter reason, Charge has been one of the most closely monitored keywords by the development team, since it has the potential to result in huge turns of burst damage, which some consider oppressive to gameplay. Doomguard and Leeroy Jenkins are some of the most recognizable Charge minions. Warsong Commander, even post-nerf due its use in the Patron Warrior deck, is the sole Charge support at the time of writing this.
A Secret is a type of spell that functions very differently from most others. Unlike other spells, Secrets stay on the battlefield and are indicated by a question mark symbol behind the user’s hero portrait. The opponent cannot see what Secret is played until it is triggered. Secrets have specific conditions under which they activate, but they are restricted to activating on the opponent’s turn. There is one exception, Competitive Spirit, which activates at the start of the player’s turn when there is at least one friendly minion in play. When a player uses a Secret, the mana cost is paid immediately, not when the card triggers later. Currently, three classes have access to Secrets, and each Secret within that class costs the same amount: one for Paladin, two for Hunter, and three for Mage. This prevents the opponent from guessing the Secret based on its mana cost. The card type is similar to Traps in Yugioh or Instants in Magic: the Gathering, but none of them have any user input after they are played. This is a result of the design decision to prevent player interaction on the opponent’s turn. The number of Secrets in play is limited to five per player, and a Secret cannot be played if there is already a copy of it on the board. The success of Secrets in competitive play has been aided by Mad Scientist, Mysterious Challenger, and Eaglehorn Bow, among several other support cards. While many Secrets are seen frequently, Freezing Trap, Ice Block, Mirror Entity, and Avenge are among the most well-known.
Generally, when minions do battle, each does damage to the other’s health equal to its own attack value. Simple mathematics. However, Divine Shield changes things, ignoring the first damage taken by a minion, including battle, spells (such as Arcane Missiles), effect damage (from cards like Knife Juggler), and so on. After the first damage is taken, the Divine Shield is removed. A minion cannot have two Divine Shields, and it is not a type of Battlecry effect: Divine Shield minions summoned through alternate means, like through Piloted Shredder, will enter the Battlefield with Divine Shield, whereas Battlecry effects don’t activate through these means. While the keyword is most prevalent among Paladins, there are neutral cards with Divine Shield. Some of the most popular Divine Shield cards are Annoy-o-Tron, Shielded Minibot, Tirion Fordring, and Al’Akir the Windlord. Blood Knight is the sole related card to Divine Shield.
The hallmark mechanic of The Grand Tournament, Inspire is an effect that activates when the controlling player uses their Hero Power. The design justification for this effect is to make Hero Powers a more central element of a deck’s strategy, rather than something to do when there are no other cards to play. The Inspire effect occurs after the Hero Power activates and resolves. For instance, when a Paladin or Shaman uses the Hero Power when Mukla’s Champion is in play, the summoned minion and all other friendly minions with the exception of the Champion will be given +1/+1. Since Inspire activates after the resolution of the Hero Power, using Life Tap at two health with a Tournament Medic in play will still result in losing the game. Similarly, using the Mage’s Hero Power against a friendly Boneguard Lieutenant at one health will destroy the minion, since it is gone before its effect activates to increase its health. Because Inspire cards make particularly good use of the Hero Power and Arena play tends to support slower, less explosive plays, they are often good picks for the format. Some of the most popular Inspire cards are Murloc Knight and Savage Combatant, seen respectively in Mid-Range Paladin and Mid-Range Druid.
Overload is a phenomenon relegated to the Shaman class that restricts the available mana of the following turn by the amount listed. It is a way to balance cards for the class, allowing under costed cards with the debt to be paid on the following turn. Basically, Shamans using Overload cards sacrifice the power of the following turn for tempo, making better plays now. If a player Overloads for more mana than is available the following turn, the extra overload does not carry over to the next turn afterward. The amount of Overloaded mana crystals for the current turn (from Overload cards played the previous turn) is shown by lock symbols over the turn’s mana crystals, and the number of Overloaded crystals for the following turn is shown by lock symbols underneath the current turn’s crystals. The enemy’s Overloaded mana crystals are not directly visible, but they can be calculated from the turn history on the left side of the screen. One quirk is that a spell with Overload that is Countered by Counterspell buffs Tunnel Trogg and Unbound Elemental but does not Overload the next turn’s mana crystals. Some of the most popular cards with Overload are Doomhammer, Crackle, and Lightning Storm. Tunnel Trogg, Unbound Elemental, and Lava Shock all either benefit from Overload cards being played or help to mitigate the negative effects.
Choose One is a keyword limited to the Druid class, allowing the player to choose one of two effects when a card is played. Visually, the effect is similar to Discover or Tracking, with cards enumerating each option superimposed onto the battlefield. The Choose One mechanic lends Druids versatility that is not found in other classes; while each individual effect may be (but is not necessarily) rather underwhelming, the ability to choose based on the situation is quite important. Presently, all Choose One cards give two choices. There is some inconsistency in wording for Choose One minions, based on the early decision to present them as modified versions of the original card. This was supposed to allow easier direct comparisons for players, but it led to ambiguity, framing Choose One effects on minions like Ancient of War as different stat buffs, rather than completely new Transformations. Recently, clarity and consistency have been a larger goal in development, leading to more explicit Transform effects. Choose One can be bundled into minions or spells. Some of the most popular Choose One cards are Druid of the Claw, Wrath, Keeper of the Grove, and Ancient of Lore.
Stealth, as alluded to earlier, essentially does the opposite of Taunt. Whereas Taunt forces the opponent to only attack minions with the keyword, Stealth minions cannot be attacked at all. They also can’t be manually targeted by an enemy spell, Battlecry, or anything else (they can still be targeted by friendly effects of this kind.) However, they are vulnerable to anything else, including area of effect cards like Flamestrike, random damage effects like Flame Juggler, and Secrets like Repentance. Stealth is not permanent: a minion loses the Stealth effect when it attacks or deals damage. The latter is true of non-combat damage, such as summoning a minion when a Knife Juggler with Stealth is in play. Another niche scenario is when a Stealth minion with above zero attack is attacked by a minion with the card text “50% chance to attack the wrong enemy.” Although it didn’t attack, doing damage through combat is enough to remove the Stealth effect. Popular Stealth minions include Shade of Naxxramas and Worgen Infiltrator. Hunter’s Flare spell has the unique ability to remove Stealth from all minions.
Spell Damage is an effect that alters the damage output of, well, spells that do damage. It does not affect the damage output of minion or weapon effects, like Fire Elemental and Death’s Bite. The most common Spell Damage effects increase output by one, but there are others, such as Malygos and Jungle Moonkin. Although it does not have the keyword, part of Prophet Velen’s effect functions identically to Spell Damage, and the multiplicative effect is calculated after any additive effects. For example, playing Moonfire while Prophet Velen and Jungle Moonkin are in play results in six damage (one from Moonfire, plus two from Moonkin, times two from Velen.) Spell Damage effects interact differently with different types of spells. Fireball, for instance, is easy enough. It simply deals six damage, plus the total amount of Spell Damage. However, for spells that do damage in a series of hits, like Avenging Wrath, Spell Damage modifiers don’t alter each hit but rather add additional hits. Playing Avenging Wrath while Azure Drake is on the battlefield results in nine damage, dealt to random opponents. Spell Damage also applies to spells with multiple defined targets, increasing the output on each minion or hero. For instance, Spell Damage +1 with Hellfire deals four damage to all characters, and with Swipe, five damage is dealt to the target, in addition to two damage to all other enemies. Bloodmage Thalnos, Malygos, and Azure Drake are some of the most popular Spell Damage cards, with Arcane Blast and Master of Ceremonies as support.
After the slog of intricacies that Spell Damage presents, Windfury is rather simple. A minion with Windfury may attack twice per turn. This ability is prevalent among, but not restricted to, Shaman cards. However, there are still a few quirks to consider. First, the effects do not stack, meaning a Windfury minion that is granted Windfury through a card effect can still attack only twice. Also, if a minion or hero gains Windfury after its first attack, it may attack again. That’s right, hero. Doomhammer is the one card, currently, that allows a hero to attack twice. Applying the last two principles, a Shaman can attack with Powermace, then equip Doomhammer, allowing it to attack one more time. Windfury minions, along with Charge minions, threaten some of the highest damage outputs. They are particularly useful with attack buffs, since the impact of said buff will be effectively doubled. Some of the most popular Windfury cards are Doomhammer, Whirling Zap-o-matic, and Raging Worgen.
Above, I’ve only listed the most popular keywords and abilities. Others, such as Discover, Freeze, and Combo are either newer or more niche. I’ll consider these, along with detailed explanations of mechanics like “Summon” and “Transform” in a companion piece. For the newest players, learning these keywords is a great start to having a better understanding of the game. Having a working knowledge of card effects makes following an opponent’s turn more manageable, allows more tactical, strategic gameplay, and makes custom deck building an easier task. Every game is a learning experience, so get out there, see what keywords and abilities you can pick out on your own, and keep exploring the wide world of Hearthstone!