Thunder IV (Final Fantasy XIV)

Thunder IV is a spell from Final Fantasy XIV that deals area of effect (AoE) damage and additional damage over time. It is upgraded from at level 64.
==Mechanics==
PvE version 	PvE version
Base mechanics	
*Deals magic lightning damage to target and nearby enemies
*Inflicts for 18 seconds, dealing additional damage every 3 seconds
*Only one Thunder effect of any level per caster can be inflicted upon a single target
*Activates the global cooldown
Traits 	
* gives Thunder IV a 3% chance per damage over time tick to grant , causing the next Thunder spell of any level to add its full damage over time amount to its initial damage, have no cast time, and cost no MP
* increases damage by 30%
Formulae 	Base direct damage formula:Damage = \lfloor Potency * f(Intelligence_{DMG}) * f(Determination) \rfloor * f(Magic Damage) \rfloor * 1.3 \rfloorWhere Potency can be 230 with Thundercloud or 50 without.
Formulae 	Base damage over time formula:Damage = \lfloor 30 * f(Magic Damage) \rfloor * f(Intelligence_{DMG}) \rfloor * f(Spell Speed) \rfloor * f(Determination) \rfloor * 1.3 \rfloor +1
Formulae 	Cast time formula:Cast = \lfloor ( 100 - Haste ) * \lfloor ( 2 - f(Spell Speed) ) * 3000 \rfloor / 1000 \rfloor / 100 Cast time becomes instant with Thundercloud.
Formulae 	Recast time formula:Cast = \lfloor ( 100 - Haste ) * \lfloor ( 2 - f(Spell Speed) ) * 2500 \rfloor / 1000 \rfloor / 100
PvP version 	PvP version
*Deals magic lightning damage to target and nearby enemies
*Inflicts for 15 seconds, dealing additional damage every 3 seconds
*All Thunder spells grant for 10 seconds if a target is dealt a certain amount of damage while under their effects, replacing the next or with or Thunder IV
*Thunder IV's damage threshold is 4000
*Thunder IV effect is removed upon gaining Thundercloud
*Only one Thunder effect of any level per caster can be inflicted upon a single target
*Activates the global cooldown	
*Deals magic lightning damage to target and nearby enemies
*Inflicts for 15 seconds, dealing additional damage every 3 seconds
*All Thunder spells grant for 10 seconds if a target is dealt a certain amount of damage while under their effects, replacing the next or with or Thunder IV
*Thunder IV's damage threshold is 4000
*Thunder IV effect is removed upon gaining Thundercloud
*Only one Thunder effect of any level per caster can be inflicted upon a single target
*Activates the global cooldown
==Use==
Thunder IV is used to deal damage over time (DoT) to multiple enemies. 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 IV 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 IV from stacking with , which is preferred in single-target encounters.
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 trait grants each damage tick of Thunder IV a 3% chance to grant the 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 IV becomes one of the most powerful AoE spells available to a Black Mage. Despite this Black Mages shouldn't use a Thundercloud Thunder IV until either the previous DoT or Thundercloud itself are about to run out in order to maximize the damage of the previous DoT. will guarantee a Thundercloud proc on the next Thunder spell used, and it is generally preferable to use it in this manner than for the other effects it provides.
As Thunder IV has a cast time longer than the global cooldown (GCD), it can pair well with and if the caster has Thundercloud. Without Thundercloud is a better use use of these abilities.
===PvP===
In PvP Thunder IV is instant cast with no MP cost. Thundercloud now activates whenever the target takes 4000 damage while under the effect of Thunder IV, which also ends the DoT effect. Thundercloud's effect is changed to instead upgrade and to the much stronger and Thunder IV, and Thundercloud is consumed in using the stronger spells.
Thunder IV's damage threshold to activate Thundercloud is lower than that of the single-target variations, allowing Black Mages to more easily activate Thundercloud without needing to focus on a specific target. Since Thunder III and Thunder IV can generate their own Thundercloud procs, it is possible to chain Thundercloud spells together.
As an instant cast spell that activates the global cooldown (GCD), Thunder IV can be used to weave abilities that are off the global cooldown (oGCD), such as , in between spellcasts.
== Patch history ==
Version 	Changes
Stormblood 	Added with an instant cast time and 18% base MP cost.Thundercloud had a 12 second duration.
Patch 4.2 	Thundercloud duration increased to 18 seconds.
Shadowbringers	MP cost set at 400 with MP system overhaul.
Patch 5.1 	New PvP exclusive version added. See below for its patch history.
Version 	Changes
Patch 5.1	Added.
Category:Black Mage actions in Final Fantasy XIV