This includes items and quests that can no longer be obtained.
The in-game information in this article is kept purely for historical purposes and should probably not be under any other categories.
Illumination
After getting a critical effect from your Flash of Light, Holy Light, or Holy Shock heal spell, gives you a X% chance to gain Mana equal to 30% of the base cost of your spell.
After getting a critical effect from your Flash of Light, Holy Light, or Holy Shock heal spell, gives you a X% chance to gain Mana equal to 30% of the base cost of your spell.
After getting a critical effect from your Flash of Light, Holy Light, or Holy Shock heal spell, gives you a chance to gain Mana equal to 30% of the base cost of the spell.
Illumination is a talent in the Holy tree, you will need to spend 15 points in Holy to max it.
Prior to Patch 2.1.0, Illumination granted a 100% mana gain after a related crit. While 2.1 was being tested on the PTR, the "new" Illumination talent was initially 50% before being adjusted to 60% for release. This resulted in many Holy-specced Paladins who had been focusing on spell critical strike gear to change their focus to equipment that provided more mana per 5 seconds.
Patch 3.2.0 (2009-08-04): This talent now returns 30% of the mana cost of the spell instead of 60%.
Patch 2.1.0 (2007-05-22): This talent now only gives 50% of the mana cost of the critical heal. It also now returns the correct amount of mana when used with ranks 4 and 5 of Holy Shock.
Edit
Patch 3.2.0 (2009-08-04): This talent now returns 30% of the mana cost of the spell instead of 60%. 
Patch 2.1.0 (2007-05-22): This talent now only gives 50% of the mana cost of the critical heal. It also now returns the correct amount of mana when used with ranks 4 and 5 of Holy Shock. 
