Summary of changes to Balance:
Balance Energy is a bar that automatically cycles back and forth between Lunar and Solar sides, like night and day. The closer to one end that the bar is, the more damage that side's spells do.
Balance Druids now have four rotational spells.
Starfire: Lunar direct damage spell
Cast when the Lunar side is stronger
Wrath: Solar direct damage spell
Cast when the Solar side is stronger
Moonfire: Lunar periodic damage spell. While closer to Solar, this button is replaced with Sunfire, a Solar periodic damage spell.
Maintain both effects where possible
Starsurge: Direct damage spell that benefits from whichever side is stronger. Has up to 3 charges, and buffs the damage of the next few Wrath or Starfire.
Cast when able to follow up with a few strong Wrath or Starfire.
That's the basics of the new Moonkin rotation. There’s room for improvement beyond that, learning to optimally maintain both periodic damage effects with the strongest Eclipse effect, timing Starsurges to optimize the benefit of its buff, make use of Starfall and Hurricane for area damage, and taking advantage of the strengths of each side (such as Moonfire and Sunfire having significant differences now). Here are the full details of the changes.
Balance Energy system has been redesigned. Balance Energy is a bar that cycles back and forth between Lunar and Solar sides, like night and day, with a 30 second cycle time (from Lunar to Solar and back to Lunar).
Balance Energy is no longer generated through spells, talents, or other effects anymore.
Eclipse has been redesigned.
Eclipse inspires the Druid with the power of the moon and the sun, causing the damage of Lunar and Solar spells to be increased by up to 30% based on how close Balance Energy levels are to the appropriate side.
Example: With 0 Balance Energy, the damage bonus is evenly split between Lunar and Solar, and the Druid receives a 15% increase to damage for both spell types. With 80 Solar Energy, the Druid receives a 27% damage increase to Solar spells and a 3% damage increase to Lunar spells.
Mastery: Total Eclipse now increases the maximum damage bonus of Eclipse by 12% (increasing with Mastery).
Starfire now has a 3 second cast time (up from 2.7 seconds).
Moonfire now has a 16 second base duration (up from 14 seconds), but is no longer extended by Starfire and Starsurge critical strikes.
Sunfire now has a 16 second duration (up from 14 seconds), but is no longer extended by Wrath and Starsurge critical strikes. Additionally, Sunfire is no longer its own spell. Sunfire replaces Moonfire on the action bar whenever Balance Energy is on the Solar side. Enemies may still suffer from both Moonfire and Sunfire’s periodic damage components simultaneously.