Arcane Blast redesigned, and Mages get Frost Blast

Every Mage tree changes in the October 15 beta build. A new spell, Frost Blast, is learned at level 24: a 1.5-second cast that deals damage, slows movement by 40% and benefits from every talent that improves Frostbolt. Blizzard added it to do what rank 1 Frostbolt did before down-ranking was penalized. It costs more mana and hits a little harder.

• Arcane: Arcane Blast is redesigned as a 1.5-second cast. Each cast gives you Spell Damage equal to 15% of your Intellect and raises its cost, stacking 4 times for 15 seconds from the first stack. Its damage and Spell Damage coefficient both drop 40%. Arcane Wrath is a new 16-point gold medal talent: a 3.5-second cast on a 6-second cooldown, with Fireball-like base damage plus damage as if you had Spell Power equal to 5% of your maximum mana. Missile Barrage moves to the first row as a 2-point talent, and Arcane Missiles hits can now trigger it.
• Fire: Fire Blast always adds a Heating Up charge, so its critical strikes add two, and Presence of Mind no longer spends Heating Up on Pyroblast. Wake of Fire is Improved Fire Blast again, extending Fire Blast’s range by 8 or 15 yards. Critical Mass goes to 5 points for 10% crit. Fire Power is a 3-point talent: 1, 2 or 3% more Fire damage per Fire effect of yours on the target, up to 12%.
• Frost: Ice Lance does 200% more damage to frozen targets (was 300%). Cone of Cold slows its first 4 targets by an extra 10% for 3 seconds longer. A bug that kept Frostbite and Fingers of Frost from triggering off Ice Armor and Frost Armor is fixed, and Frost Channeling now correctly lowers threat.

The notes describe Winter’s Chill two ways. One line says it no longer raises critical strike chance and instead raises Cone of Cold’s damage by 40% per stack, consumed by the next Cone of Cold. A later line has Frostbolt, Frost Blast and Ice Lance empowered by Fingers of Frost apply it at 20 to 100% chance, each stack adding 5% damage and 7% of your spell damage to your next Cone of Cold, up to 5 stacks.

Why it matters: Arcane plays very differently from the last build, and every Mage gets a new slowing spell at level 24, so check your talents after the update.