Thunder is used to deal damage over time (DoT) to the target. It should always be applied as soon as possible against a target to maximize its effects. Against weak enemies expected to die in less time than its duration it may be safely skipped. Thunder is best used during the Umbral Ice state, as the MP it consumes will not regenerate in the Astral Fire state and it doesn't benefit from the state's damage increase.
Only one Thunder spell-induced damage over time effect per caster can be inflicted upon a single target, preventing Thunder from stacking with Thunder II.
DoT effects deal damage every server tick, or 3 seconds, independent of the effect's duration. This means that the effect may deal damage anywhere between 0 and 3 seconds after it is applied, and in 3 second intervals afterwards. In order to maximize efficiency on damage over time effects, it is generally recommended to reapply them with under 3 three seconds remaining, as the final tick of damage from the effect can occur anywhere in that window. This may result in the loss of a tick, but waiting for the effect to drop off before reapplying can result in the loss of two or more ticks and greater DPS loss.
The Thundercloud trait grants each damage tick of Thunder a 10% chance to grant the Thundercloud status. The status causes the next Thunder spell of any grade to add its full DoT amount to its initial damage, have no cast time, and cost no MP. With Thundercloud active, Thunder becomes the most powerful spell available to Black Mage at lower levels. Despite this Black Mages shouldn't use a Thundercloud Thunder until either the previous DoT or Thundercloud itself are about to run out in order to maximize the damage of the previous DoT.
In PvP Thunder is instant cast with no MP cost. Thundercloud now activates whenever the target takes over 8000 damage while under the effect of Thunder, which also ends the DoT effect. Thundercloud is now part of the base ability, and its effect is changed to instead replace Thunder and Thunder II with the powerful Thunder III and Thunder IV. As Thundercloud only activates when the affected target takes heavy damage, Black Mages should focus their damage on the affected target to ensure Thundercloud activates.
As an instant cast spell that activates the global cooldown (GCD), Thunder can be used to weave abilities that are off the global cooldown (oGCD), such as Night Wing, in between spellcasts.
|A Realm Reborn||Added with 35 DoT potency and 8% base MP cost.|
Thunder and Thunder III were distinct spells, but all Thunder spells applied the same Thunder status and could not stack.
Was available as an additional action to Arcanists, Summoners, Scholars, Conjurers, and White Mages.
Thundercloud had a 5% chance to activate after each damage over time tick inflicted by any Thunder spell and had a 12s duration.
Had a base potency of 240 under the effect of Thundercloud.
|Patch 2.1||No longer available as an additional action.|
|Patch 3.05||DoT potency increased to 40.|
Thundercloud activation chance increased to 10%.
Base potency while under the effect of Thundercloud increased to 270.
|Stormblood||Thunder III now replaces Thunder via the level 45 trait Thunder Mastery.|
Each Thunder spell now inflicts their own unique status, but these statuses still cannot stack.
Thundercloud activation chance reduced to 3% for Thunder II.
No longer available in PvP. New PvP exclusive version added. See below for its patch history.
|Patch 4.2||Thundercloud duration increased to 18s.|
|Shadowbringers||MP cost set at 200 with MP system overhaul.|
|Stormblood||Added with 500 initial potency, 300 DoT potency, 1500 MP cost, 1.8s cast time, and 2.3s recast.|
Granted the Thunder III Ready status for 10s if target took 6000 damage while Thunder was active, and removed the Thunder status.
Replaced by Thunder III while Thunder III Ready was active.
|Patch 4.05||Damage threshold reduced to 5000.|
|Shadowbringers||Initial potency reduced to 400.|
DoT potency increased to 400.
MP cost reduced to 1000.
Cast time reduced to 1.5s.
Recast time increased to 2.4s.
|Patch 5.1||MP cost reduced to 0.|
Damage threshold increased to 6000.
Thunder III Ready renamed to Thundercloud.
Thundercloud now also replaces Thunder II with Thunder IV
Only one Thunder spell-induced damage over time effect per caster can be inflicted upon a single target.
|Patch 5.3||Cast time reduced to instant.|
|Patch 5.58||Damage threshold increased to 8000.|
Behind the scenes
Thunder appeared as an ability in the original version that dealt lightning-elemental damage to the target and nearby enemies. At the initial release, Thunder was a Conjurer spell available for use at Rank 1 and it cost 3 action points to set. After the release of patch 1.20, Thunder became a Thaumaturge spell available at level 1 and only damaged a single enemy.