Hotfix (2022-12-12): Can no longer be dispelled (previously had the magic dispel type).
Patch 10.0.0 (2022-10-25): Now a row 6 Fire talent (was a level 29 Fire ability). No longer grants mastery equal to 50% of your critical strike stat; that and Rank 2's effects have split off to become [Improved Combustion].
Patch 9.0.2 (2020-11-17): Rank 2 added at level 56: Duration increased by 2 seconds.
Patch 9.0.1 (2020-10-13): Now learned at level 29 (was 40).
Patch 8.0.1 (2018-07-17): Now only affects Mage spells, and no longer interacts with non-mage spells such as damaging trinket procs.
Patch 7.1.5 (2017-01-10): The amount of Mastery granted has been reduced to 50% of Critical Strike rating (was 100%). Rank 2 has been removed and its effects are once again baseline.
Patch 7.1.0 (2016-10-25): Now learned at level 40 (was 28). Combustion has been split into two ranks, the second rank granting Mastery equal to critical strike rating. Rank 2 is available at level 65.
Patch 7.0.3 (2016-07-19): Redesigned. Now increases critical strike by 100% and Mastery equal to the Critical Strike stat for 10 seconds. Cooldown increased from 45 seconds to 2 minutes. Now learned at level 28 (was 80).
Old: Resets the cooldown on Inferno Blast and combusts your Ignite on the target, burning for additional damage over 10 sec equal to 8 seconds of Ignite's current damage over time.
Hotfix (2014-11-12): Combustion is now learned at level 80 (was 77).
Patch 6.0.2 (2014-10-14): No longer deals direct damage or stuns. Damage dealt has been increased by 100%. Additionally, this ability now replaces [Deep Freeze] for Fire mages.
Patch 5.4.0 (2013-09-10): Combustion on targets affected by the Mage's Ignite now deals additional damage equal to 20% of Ignite's damage per tick (down from 50%).
Hotfix (2012-11-29): The periodic damage from Combustion has been reduced by 50%.
Patch 5.1.0 (2012-11-27): Periodic damage is now based only on the current Ignite, instead of both Ignite and Pyroblast. Damage has been increased to bring it up to approximately the same level as before.
Hotfix (2012-10-16): Combustion direct damage that does not crit now causes Heating Up to be removed after a short delay. Additionally, the delay on non-crits removing Heating Up has been increased from 0.25 sec to 0.5 sec.
Pyroblast and Combustion should combine to do the expected amount of damage and critical damage.
The initial damage of Combustion is now properly affected by Shatter, increasing its crit chance accordingly.
Hotfix (2012-09-12): Combustion should no longer ignore target damage multipliers when calculating the damage of the Pyroblast DoT on the target.
Patch 5.0.4 (2012-08-28): Redesigned as a level 77 Fire ability (was a tier 4 Fire talent). Instantly deals Fire damage and stuns the target for 3 sec. Burns the target for additional damage over 10 sec based on the Pyroblast and Ignite effects already on the target. When cast, resets the cooldown of your Inferno Blast ability.
Old: Combines your damaging periodic Fire effects on an enemy target but does not consume them, instantly dealing Fire damage and creating a new periodic effect that lasts 10 sec and deals damage per time equal to the sum of the combined effects.
Patch 4.3.0 (2011-11-29): Combustion's periodic damage can now critically hit.
Hotfix (2011-07-26): Combustion should no longer ignore damage modifiers on a target. As an example, Smoldering Elemental packs in the Firelands should no longer take full damage from Impact’s spread of Combustion, despite these creatures having damage reduction modifiers.
Patch 4.1.0 (2011-04-26): No longer has a global cooldown.
Patch 4.0.1 (2010-10-12): Redesigned. Combines your damaging periodic Fire effects on an enemy target but does not consume them, instantly dealing Fire damage and creating a new periodic effect that lasts 10 sec and deals damage per time equal to the sum of the combined effects. Moved to tier 4 and no longer requires [Critical Mass].
Old: When activated, this spell increases your critical strike damage bonus with Fire damage spells by 50%, and causes each of your Fire damage spell hits to increase your critical strike chance with Fire damage spells by 10%. This effect lasts until you have caused 3 non-periodic critical strikes with Fire spells.
Patch 3.3.3 (2010-03-23): The cooldown on this spell is now 2 minutes, down from 3 minutes.
Patch 3.2.2 (2009-09-22): This talent now also increases the critical strike damage bonus of Fire spells by 50% while it is active. In addition, [Living Bomb] periodic ticks will no longer interact with the count or the charges on the talent.
Patch 3.2.0 (2009-08-04): Fire spell misses will no longer trigger this talent.
Patch 1.12.0 (2006-08-22): Reduced the number of messages that appear in the combat log when using Combustion.
Patch 1.11.0 (2006-06-19): Redesigned. When activated, this spell causes each Fire damage spell you cast to increase your critical strike chance with Fire damage spells by 10%. This effect lasts until you have caused 3 critical strikes with Fire spells. 3 minute cooldown.
Previously, it increased the critical strike chance of the next fire spell by 100%, only guaranteeing one critical strike. The cooldown was 5 minutes.
Classic[]
Hotfix (2020-08-28): Fixed a bug that unintentionally allowed Combustion to apply a permanent buff to crit chance.
References[]
^Thyst on Twitter (2020-03-12). “So last night @JeffAHamilton told my raid that you can cook on Combusting Mages. I asked to be cooked on. I can be cooked on. You can cook on Mages. #TheMoreYouKnow #EasyMageOven #Warcraft!”
[Critical Mass] or 
[Intensifying Flame] or 
[Flame On]
[Improved Combustion]/
