Haste Haste increases attack speed and reduces the cast time of spells . Haste stacks in a multiplicative manner . This means that it is beneficial to stack multiple haste effects . For instance , stacking Slice and Dice with Blade Flurry ( Rogue abilities ) gives a total of 68 % haste ( 140 % * 120 % = 168 % of the base attack speed ) . Haste rating stacks additively with itself ( two sources of 100 haste rating give 200 haste rating stacked together ) and then is converted into a percentage that stacks in a multiplicative manner with other sources of haste . For every 32 . 79 points of haste rating you will have 1 % faster attack speed at level 80 . The formula for determining weapon haste speed at level 80 is : formula _ 1 Example : Beast Master Hunter formula _ 2 Cataclysm . In " " , haste will also increase the rate at which you gain energy , rune s , and focus . Retribution paladin s and Enhancement shaman will have a talent that allows them to take advantage of this benefit . Wrath of the Lich King . Early numbers are showing a 32 . 79 rating required at level 80 to achieve a 1 % gain in speed . Patch 3 . 1 . Quivers and ammo bags no longer grant haste . Instead , the haste from quivers and ammo bags has been built into Auto - Shot . Some classes ' haste got buffed and now 25 . 21 Haste Rating provide 1 % melee haste for Death Knights , Druids , Shamans , and Paladins and Warriors . As of patch 3 . 0 , Haste Rating also increases your Spell haste . Previous patches . Patch 2 . 2 . 0 . Haste has been rebalanced . It has returned to the ratios from the launch of Burning Crusade . Melee attacks and spell casts will now benefit at identical rates from haste . This change results in a reduction in the benefit of haste for melee attacks and an increase in the benefit for spellcasters . Patch 2 . 1 . 0 . The amount of haste granted by a point of haste rating is being reduced again . See combat rating system for current rating effects . 10 haste rating gives 1 % haste at level 60 . Patch 1 . 12 . Previously , haste and slow effects worked inconsistently , with spells working differently from weapons , and hastes and slows not acting as inverses of each other . We have revised the system so that all haste and slow effects work the same way , and haste and slow percentages of the same magnitude perfectly cancel each other out ( 30 % haste and 30 % slow combine to no change ) . As a result , we had to change the tooltip numbers on all spell haste effects , and on all melee and range slow effects . The numbers in the tooltips are different , but the game functionality is unchanged ( other than slight rounding errors ) . Those tooltips that changed will now display larger numbers than they used to display . Conceptually , haste values indicate how much more of that activity you can perform in a given time . 30 % melee haste means 30 % more swings in a given time . Slow values indicate how much longer an activity takes to complete . 30 % slow means an action takes 30 % longer to finish . Haste now stacks in a multiplicative manner . In development . Changes are likely coming for haste in Patch 3 . 3 . 0 . Here ' s a post from the lead developer describing some changes that might be seen : More detailed comment regarding all stats for Patch 4 . 0 . 1 and eventually , but here referencing only haste .