Ice Shards ( removed mage talent ) < onlyinclude > < / onlyinclude > Ice Shards is a mage talent that increases the mage ' s critical strike damage bonus for Frost spells by 33 % per rank , up to 100 % at max rank 3 . Ice Shards is present in many frost builds , as it is a key talent for increasing frost damage output . Since this talent only improves damage done by crits , it combines well with talents that increase frost crit chance . Shatter is a popular talent for increasing critical strikes , combined with other talents and abilities that help Shatter by increasing freeze opportunities , such as Frostbite . Also , Empowered Frostbolt , Arcane Instability and Arcane Potency all directly increase critical strike chances for frost spells , without relying on Shatter . Mathematics . Spell critical strikes normally add a bonus equal to 50 % of the base spell hit , meaning a hit for 1000 damage will crit for 1500 damage . The talent percentage is applied to this bonus damage , doubling the bonus at Rank 3 . This means that with Rank 3 Ice Shards , a spell that normally hits for 1000 damage will crit for 2000 damage . The following formula will compute a critical strike given base spell hit damage , where X is the number of points in Ice Shards : Ice Shards stack s with the talent Spell Power . With both talents at max rank , a Frost spell that hits for 1000 will crit for 2250 , a bonus of 1250 damage . The following formula will compute a Frost critical strike with both talents , where X is the number of points in Spell Power and Y is the number of points in Ice Shards : Burst damage . Ice Shards increases your crit multiplier by + 0 . 166 per point you spend on the talent . Long term damage . This is a formula that calculates how much of a boost in long term damage ( over a large number of spell casts ) you can expect to get from this talent when using frost spells that can crit . The formula uses the " three outcomes " model , as well as a concept from probability theory called expected value . This calculation does not take into account resists and partial resists . Mathematical derivation . The " three outcomes " model states that in WoW , when one casts a spell there are three possible results : a hit , a critical hit , or a miss . If we know the probability of each outcome , we can use probability theory to calculate the expected value of damage . Then , we can calculate the percentage difference in damage we can expect to see from various crit rate / hit rate / talent point combinations . [ ( chance to crit ) × ( crit damage ) ] + [ ( chance to hit and not crit ) × ( average damage ) ] + [ ( chance to miss ) × 0 ] Without Ice Shards , the expected amount of damage one does with spells is : C×1 . 5×A + ( H−C ) ×A + ( 1−H ) * 0 With Ice Shards , one expects : C× ( 1 . 5 + ( T / 10 ) ) ×A + ( H−C ) ×A + ( 1−H ) ×0 The percentage difference would be : This expression simplifies to : T×C / ( 5C + 10H ) < br > ∀ T = { 0 , 1 , 2 , 3 , 4 , 5 } , 0 ≤ C ≤ 1 , 0 ≤ H ≤ 1 , and ( H - C ) ≥ 0 Results . Essentially , this result states that the increase in long term damage you get from this talent depends on three variables . The first variable is T , the number of talent points you spend on the Ice Shards talent . The second variable is C , your crit rate . And the third and final variable is H , your chance to hit . This result may seem counter - intuitive ( i . e . lower hit rates leads to higher bonus ) . This is a consequence of the the " three outcomes " model . Crits and hits share the same " probability space " , and therefore hit rate puts a cap on crit rate . It must be thought of in this way : if you are missing more often , then the critical hit to " normal " hit ratio is higher .