Mage · Frost · tier 3 · from level 20

Piercing Ice

+68.3 Blizzard

3/3 · level 60 · per cast · and 4 more

Piercing Ice 123

Rank 3/3

Increases the damage done by your Frost spells by 6%.

Blizzard +6.0% +68.3 Frostbolt +6.0% +27.8 Frostfire Bolt +6.0% +20.4 Cone of Cold +6.0% +20.1 Frost Nova +6.0% +4.4

Averages, counting crits and misses, for a level 60 Mage with a typical weapon and no other gear or buffs, against a target your level. Worked out from the game's own data, the same way as the Foresight addon.