Haste Explained: How it affects HOTs and DOTs
As of patch 4.01 Blizzard changed how haste affected both Heal over Time (HOTs) and Damage over Time (DOTs). Prior to patch 4.01 and Cataclysm haste affected the overall time that a HOT or DOT lasted and applied the same number of ticks but over a shorter period of time. Now, however, DOTs and HOTs last the same duration with haste as without but have the duration between ticks shortened. This means that if you have enough haste your spells can gain extra ticks gaining a ton of effectiveness.
While many hard-core players and raiders picked up on the importance of this change, many casual players still do not really understand what it means for you and how really critical it is.
To make it even more complicated it is not as easy as just stacking haste to get as much as you can. Instead there are what are called break points or plateaus that are what you need to aim for to maximize its benefit. Before we get into that though, let’s look at why this change is so important and then the calculation itself.
Why is this important?
So why is speeding up the rate at which your HOTs and DOTs tick so important? What’s the big deal? I’ll show you using an example from a resto druid, which does much of her healing through HOTs.
One very important HOT is Rejuvenation, it is an instant cast spell that at level 85 and with some decent gear costs roughly 5000 mana and heals for 3600 health every 3 seconds for 12 seconds.
This means that with no haste it will heal for 3600 health 4 times. So ignoring any that crit it will heal for a total of 14,400 health. The heals will come at the 3, 6, 9, and 12 second marks.
Now if we assume that we have over 12.5% haste then Rejuvination gains an extra tick (more on this later), then instead of 3600 health 4 times, it ticks 5 times. This means it heals for a total of 18,000.
It’s obvious to see the difference it makes due to the increase in healing. After all, an extra tick essentially grants 3,600 worth of free healing. However, that isn’t the full story either. Look now at the efficiency of the spell. In base form it heals 2.8 health per mana, with haste it is now healing 3.6 health per mana. This extra healing per mana point will greatly extend your overall healing time, since you can in theory cast fewer heals that will heal for more.
The Math behind the Magic
There are several calculations you can use to figure out the haste required to reach another tick on any of your HOTs or DOTs.
The first and most basic is a check against the haste that you have and then checking to see if the number works out to be another tick. This means working it out each time you have a new total of haste though, and checking each spell, so it is a bit cumbersome, but a great way to understand the math behind haste.
To do this you use the following calculation:
Spell Duration / ( Base Tick Time / ( 1 + Haste % in decimal form)) = Total Number of Ticks Rounding Up
Therefore, using the example above regarding rejuvenation you can see that:
(12 / ( 3 / ( 1 + 0.125 ))) = 4.50001
While it looks like you would still be at only 4 ticks, the game actually rounds up. That is why the break points for rejuvenation comes at 12.5% and then not again until much later, more on this in the break points section.
The other way to calculate haste effects is by specifically calculating for the extra number of HOT or DOT ticks that you would like to gain. You can do this using the following three calculations, the first figures out how fast your HOT or DOT needs to tick to fit into the spells duration, the second calculates the haste rating percentage needed to get it to do so, and the third figures out the haste rating required.
NOTE: These calculations are not original, as they are based on the game and it's mechanics, and as such can be found on several other sites such as ElitistJerks, wowwiki, the official forums and many more.
( Base Ticks x Base Tick Speed ) / ( Desired Ticks – 0.5 ) = Required Tick Speed
Again back to our rejuvenation example we can fill it in as follows:
( 4 x 3 ) / ( 5 – 0.5 ) = 2.666666
Now we move onto the second part of the calculation, how much haste do we need to hit the newly calculated Tick Speed.
( Base Tick Speed / ( Required Tick Speed + 0.00049999 )) – 1 = Haste Percentage Required
NOTE: The 0.00049999 coverts to 0.049999% which is the precision that Blizzard checks to see if you are over a break point.
Back to our example yet again to calculate rejuvenation yet again and it is:
(3 / (( 2.666666 + 0.00049999 )) - 1 = 0.124789 or 12.4789%
This shows quite clearly why I used the 12.5% in the example to start with and proves the math behind it.
Lastly, knowing that at level 85 you need 128.2 haste rating to earn 1% haste you can figure out the haste rating required by using this equation:
128.2 x Haste Percentage Required = Haste Rating Required
Once again with the rejuvenation example this works out to:
128.2 x 12.4789 = 1600
Break Points / Plateaus
Now let’s move onto how to actually use this information now that you know the math behind it. As we all know each class has several different stats that are important to them. This time let’s look at a Warlock to use as an example.
We know that causing damage is important to a Warlock and that to do so the stats that are of key importance to them are Intelligence, Hit, Haste and Crit. So assuming that as a Warlock you are getting gear with as much intelligence as possible and are already hit capped, what next? Since Haste gives more damage from the same spell and mana it is really important, but then again so does crit.
This is where break points or plateaus come into effect. As I have shown above Haste is important to get that next free tick from a HOT or DOT, but after that does nothing for that spell (other than lowering the GCD until you hit 1) until you get a massive amount of additional haste. Crit however is a steady percentage chance increase.
Therefore what you should do is figure out the break points for your spells and gem, enchant, or refogre to hit the Haste break point of whichever highest one you can, and then put any extra reforging into crit.
Using the Warlock example lets look at three base spells that form the core of their rotations. I’ll save you the math in this section and just show the numbers that the calculations come up with.
- Corruption ticks 6 times over 18 seconds and gains an extra tick at 1067 and 3200 haste rating.
- Bane of Agony ticks 12 times over 24 seconds and gains an extra tick at 531 and 1605.
- Unstable Affliction (or Immolate for Destro Locks) ticks 5 times over 15 seconds and gains an extra tick at 1280 and 3850.
Therefore if you can reach 1450 haste with your current gear, you will gain an extra tick of each of your core abilities. However anything above 1280 is essentially being wasted as you will not gain an extra tick from any of them until you reach 1605.
So it is best to reforge haste to crit down to the 1280 required to get an extra tick from unstable affliction as the critical strike rating will provide much more of a boost.
Now to complicate this even a bit further, there are party / raid buffs that grant a flat haste increase. I mention these this far into the process as most raid players probably already understand how important haste and break points are, and this guide is mainly aimed at newer players that don’t understand and may not ever run raids or groups.
It is still important to know and understand the effects that party / raid buffs can have though. The critical ones are the 5% spell haste buffs that come from Shaman’s Wrath of Air totem, Druid’s Moonkin form, and Shadow Priest’s Improved Shadowform buffs. These all significantly lower the amount of haste you need to reach a break point by granting a flat 5% boost to haste.
Using the Warlock example from the previous section, the haste rating that you would need on your character to gain the extra corruption and unstable affliction ticks that initially required 1067 and 1280 now drops by 641 each once you have a 5% haste buff. This means that in a group situation you know only need 426 and 639 respectively. This also means that the next tick of Bane of Agony that you needed 1605 to reach now only requires 964, which you are now well over having geared for 1280.
If you are a casual player without a normal 5, 10, or 25 player group that you run with, I suggest you be aware of this difference but not to plan for it. If, however, you have a group of even 4 other players and one happens to provide that buff and you run instances with them all the time, I say work to the 5% haste boosted numbers.
Wrapping it all up
As you have hopefully learned and now understand, Haste has a huge amount going for it. The amount really depends on your class and spec, but if you are a class that has multiple HOTs or DOTs it may just be your best supplementary stat. Even if it isn’t it is well worth being aware of, and if you are just above or below a key break point you should reforge to just meet it and then focus on something else.
While you probably learned that this can be figured out fairly simply by hand calculations, but that a chart could be easier. Because of that, here are just a few of the many reference sheets out there that provide some quick break points to aim for.
Warlock - Warlock Dot Calculations - (By Keldion)
Druid (Resto) - http://www.treecalcs.com/ (by Krvas and Hamlet)
Druid (Moonkin) - http://elitistjerks.com/f73/t37800-wrathcalcs_moonkin_dps_spreadsheet/ (by Hamlet)