2.1.
New Content
Midnight Season 1 has officially launched, and with it we get lots of new
content, like three new Raids, Mythic+ opening, and the start of the PvP season.
Due to this, you get access to a new Tier-set and lots of new gearing options.
If you want to check out any of the new content, make sure to head over to the dedicated sections!
2.2.
Class Tuning
With the launch of Season 1, Arcane has received
some balance adjustments:
Arcane Blast damage increased by 25%.
Arcane Barrage damage increased by 15%. Does not affect PvP.
- Arcing Cleave additional targets receive 40% of Arcane Barrage's
damage (was 60%).
Spellslinger: 
Splintering Orbs damage bonus reduced
to 10% (was 25%).- Spellslinger:
Controlled Instincts Cleave percentage
reduced to 40% (was 60%).
These changes do not impact the playstyle or best
talents much, but it does have some minor tweaks here and there, like
with the Rotation, or the optimal Talents.
Additionally, Blizzard already announced that there will be further tuning
at the start of the second week of the season, and most likely multiple
other waves of balancing
As always, when this happens, the guide will be updated as soon as these
changes occur, or when new theorycrafting findings have been made, so make
sure to check back regularly during the first few weeks of the season.
When it comes to tuning adjustments, our next planned pass is expected to arrive
with the Midnight Season 1 launch on March 17. Our next pass will follow immediately
afterwards utilizing data gathered during the week Heroic difficulties are available;
these changes will go live with the launch of Mythic raid difficulty and Mythic+ on
March 24.
Beyond these dates, we will look to perform more tuning passes based on data gathered
during the starting weeks of Mythic difficulty for Season 1 and the March on Quel’Danas
available the week of March 31.For these two passes we err on the side of caution with
the amount of tuning we do until their respective Mythic end-bosses die to avoid being
overly disruptive to progression. After these key dates we will have several check-in passes
planned roughly a month apart. Once players obtain higher item level and better optimized gear
sets, the throughput of several specs will shift up or down relative to others and we feel
it’s important to be diligent in looking at the current state of class balance as time goes on.
2.3.
Midnight Changes for Arcane Mage
Midnight has arrived, and Arcane Mage has received a substantial rework
affecting both the Mage class tree and the Arcane spec itself.
At its core, Arcane is still about high burst and mana management, but the way
it does this is quite different. Arcane had many of its different
buffs consolidated into a single new resource: 
Arcane Salvo, to reduce
the amount of different resources and buffs to track.
2.3.1.
Apex Talent
Midnight introduced a new type of talent, called Apex Talent.
It shows up at the bottom of your talent tree, and has four ranks.
It functions similar to other talents, costing talent points like usual.
For Arcane, we get the following Apex Talent:
Touch of the Archmage: Touch of the Magi increases
the damage your target receives from you by 15%.
Touch of the Archmage: Arcane Charges further increase the damage
of Arcane Blast, 
Arcane Pulse, and Arcane Barrage.
Also increases 
Arcane Missiles damage. Has 2 ranks.
Note: This always counts, not just during Touch of the Magi.
Touch of the Archmage: When Touch of the Magi explodes,
it leaves behind a pulsing rune on its target, dealing 75%
of its damage over 6 seconds to nearby enemies. This damage
is increased by 50% on the initial Touch of the Magi target.
2.3.2.
Hero Talent Changes
Spellslinger has not received major changes, but more targeted
tuning due to the changes to the spec tree. Anything previously
referring to a buff affecting Arcane Barrage has been changed to use
the new Arcane Salvo buff. And 
Splintering Sorcery now just
procs directly from Arcane Blast and Arcane Pulse instead of
Nether Precision due to its removal.
Sunfury has received relatively few changes, mostly
focusing on reducing buff tracking. Primarily, 
Burden of Power
has been simplified so that it just makes Arcane Blast and
Arcane Pulse passively do more damage, instead of being a core
proc we played around. The same goes for 
Glorious Incandescence,
which used to be a core proc to play around. It now drops
Meteors when you consume Arcane Salvo which simply do damage,
instead of interacting with any of Arcane's resources.
2.3.3.
Core Rotational Changes
One of the primary changes is the removal of many different buffs,
like 
Arcane Harmony, 
Intuition (changed to be
passive instead of a proc), 
Arcane Tempo (also now passive instead
of a proc), etc, into a singular buff: Arcane Salvo. Arcane Salvo
is a stacking damage buff to Arcane Barrage, stacked via
Arcane Missiles by default, but many talents interact with it to
either generate it via other spells, like 
Expanded Mind giving
Arcane Blast and Arcane Pulse the ability to generate it as
well, or 
Orb Barrage increasing the chance to proc based on Salvo
stacks instead of Arcane Charges.
What all of this means, is that instead of tracking multiple different
buffs, almost all of your rotation decisions will be based around
Arcane Salvo, your Arcane Charges, and your mana level. The only
remaining exception is 
Clearcasting, which still plays
a critical part in the rotation like before, being the only way to cast
Arcane Missiles.
In practice with the way things are tuned, the spec becomes about
generating the maximum Arcane Salvo stacks as quickly as possible,
and then immediately spending them to start building them up again.
One final meaningful change is the introduction of Arcane Pulse,
which is a new ranged AoE ability. It functions very similar to
Arcane Blast, since the damage and mana scales with Arcane Charges,
except it does AoE damage. It does not fully replace 
Arcane Explosion,
as you can use both, but in most circumstances in practice it does
become your main filler ability in AoE scenarios. Since this is ranged,
this is a great quality of life improvement, as it means you will no longer
need to be in melee to do AoE damage.
2.3.4.
Other Changes
- Mage defensives have been consolidated and simplified:
►
Click to expand
Prismatic Barrier is now even stronger. When fully
talented into all supported talents it now provides more
absorption (30% max HP), and even more magic damage taken
and debuff duration reduction. It also has a lower global
cooldown, allowing you to go back to DPSing quicker.
Greater Invisibility and 
Mirror Image no
longer reduce damage taken — they are now purely
utility spells.
Mass Barrier has been removed.
Temporal Realignment has been added, which allows
you to self-heal after dropping to low health, at the cost
of some manual control over 
Alter Time. Alter Time
is normally mostly used for dealing with high burst damage,
but via Temporal Realignment, it can also be useful for
healing yourself up when you get low health from chip
damage.
- Mage Mobility has been slightly reduced and has a few tradeoffs to make
now:
►
Click to expand
Shimmer now has only 1 charge base (was 2) and a 30
second cooldown (was 25) baseline. You can gain back the
lost charge, but it is now a trade-off between
Reflection and the extra
charge.
Blink can now be improved via talents:
Spatial Manipulation grants an extra charge,
Improved Blink reduces its cooldown.
Ice Floes has been removed.
- Various utility talents have been nerfed or changed into
choice-nodes:
►
Click to expand
Shifting Power has been removed entirely.
Blast Wave has been removed from baseline (only
accessible via Sunfury talent, but very situational).
Ice Nova and 
Cone of Cold are now mutually
exclusive. 
Mass Polymorph and 
Ring of Frost are now
mutually exclusive.
Counterspell now interrupts for 7 seconds (was 5).
Spellslinger
Sunfury
