This addition to the Shaman's array of damaging attacks now gives the high potential for the Shaman to be considered an AoE farming class. With [Magma Totem] and [Chain Lightning], the shaman now has an impressive array of multi-target damaging spells.
Highly useful in raid situations usually involving lots of trash mobs. Shamans can run cast Flame Shock on one mob, use [Lava Lash] on that target to spread FS to other enemies, and then cast Fire Nova.
Fire Nova was added in patch 3.3.0 to replace [Fire Nova Totem]. While the prior Fire Nova Totem was considered a pet and thus would potentially disallow typical kill rewards (loot, exp), the new Fire Nova is a direct AoE attack, bypassing any prior pet restrictions. The Shaman [Magma Totem] and [Searing Totem] are still considered pets.
Hotfix (2015-01-12):Fire Nova now causes up to 6 novas (down from 7).
Hotfix (2014-10-30):Now has a maximum of 7 novas that can be triggered if more than 7 targets are affected by [Flame Shock].
Patch 6.0.2 (2014-10-14): Now has a cooldown of 4.5 second (up from 4.0 seconds).
Patch 5.4.0 (2013-09-10): Damage has been increased by 83%.
Patch 4.1.0 (2011-04-26): Has been redesigned and decoupled from shaman Fire totems. Instead, it now pulses the Fire Nova effect from each target that is afflicted by the shaman's own [Flame Shock] debuff. It now damages all enemies except the target hit by Flame Shock. The ability's cooldown has been reduced to 4 seconds, down from 10.