Quote Originally Posted by Morgana View Post
*sigh* No, you're only half correct. Healing monsters is based on INT/MATK, and so is healing party members. Ask any STR cleric... They can't heal themselves or their party members for more than 20 HP or so.

The in-game description is misleading. It says 300%, but it doesn't say 300% of what. The 300% is a multiplier to some unknown, hidden INT/MATK formula that the game calculates. LUK is also possibly involved, but only slightly, if at all.

Sources:
Best approximation for heal damage formula.
Afrobeans's HP cleric: here, here, here. Unfortunately, the main thread about it got deleted because it was too old...
QFT. If there was such a thing as stickying individual posts, you'd be a top runner.

The % listed is used only as a measuring stick to show your growth, it doesn't say what it's 300% of and it's easily demonstratable that it's not 300% of your HP. 100+ priests with less than 1.5k HP heal more than 4.5k HP easily.