Originally Posted by

**Shaiandra**
That's not right...

Most classes/specs start with 8.00 Mastery (Frost mages and Fury warriors are the only ones that don't), assuming you have 0 Mastery Rating from items. Since Echo of Light is 1.25% per point, this times 8.00 is 10.00%, hence the description will show 10%.

The Armory, for some reason, only shows this base value (the 10% in this case). In game tooltips will be somewhat more accurate, though it will show percentages rounded down.

13.54 total mastery means you have 5.54 mastery from gear (it's approximately ~179 rating for 1 point, so your 993 rating gives 5.54 on top of the 8 you start with), and 13.54 * 1.25 = ~16.925% of your healing is added as a HOT. But again, the armory will only show 10% regardless of your Mastery rating, and your in game tooltip might only show 16% (since it rounds down on the tooltip), but it actually will be around 16.92%.