Deal 6 damage.
This spell is useful for burning things. If you're looking for spells that toast things, or just warm them a little, you're in the wrong place.
 How to get
Fireball x 2 are automatically included in all players' collections.
Mages have a number of spells in their arsenal for dealing damage, such as Arcane Explosion, Frostbolt, Cone of Cold, and of course, Fireball. A mage must carefully consider which spells to include in their deck. While other spells do damage to more than one minion, or have secondary effects such as Freezing, or have restrictions, such as Ice Lance, Fireball has no secondary costs or effects, making it one of the most consistent spells in your arsenal.
A deck including Fireball is very unlikely to include two copies of it and no copies of any other spell. For this reason, it's important to see what spells we want to pair Fireball with. Fireball, being a single-target spell, shares a similar spot in the deck to Pyroblast, Frostbolt and sometimes Ice Lance. Pyroblast is very expensive, so it's unlikely to want to deal with the same minions as you would with Fireball. Frostbolt deals 3 less damage and freezes for 2 less mana - which leaves Fireball as the better choice, unless you think that 6 damage is 'Overkill', or you are using spell damage minions to boost the power of Frostbolt to higher damage.
Fireball does a large amount of damage to a single creature, which leaves us vulnerable as a mage to a large number of smaller creatures. A deck that includes Fireball should probably include some number of cards that help with smaller minions, such as Arcane Explosion, Blizzard, or Flamestrike.
Lastly, Fireball can target your opponent. If you want to go a direct-damage route, it can be paired with Pyroblast for maximum damage. If this is the case, you will probably want to pair the card with Sorcerer's Apprentice, Kobold Geomancer, Dalaran Mage and other Minions that assist in dealing damage.
In World of Warcraft, Fireball is a classic mage spell that has been tied to the class since its creation. Mages specialized in Fire are particularly skilled in their use, but all mages have access to the spell. Jaina Proudmoore and Archmage Antonidas (the only two named mages in Hearthstone) actually excelled in Frost spells, but were powerful enough to have intimidating spells from all schools of magic.
 Patch changes
- Alpha patch 2 (2013-08-12): Mana cost lowered to 4, from 5.