There are many effects in the game which deal periodic damage over time (DoT) or healing over time (HoT). Historically, these have typically done something called "snapshotting"; they were based on your stats at the time that they were cast, and that was used for calculating their effect for their full lifetime. In Mists, if a warlock casts Corruption on an enemy while Heroism is active, that DoT will continue to tick rapidly based on the temporary haste effect, even after Heroism fades. This has led to some gameplay that has both good and bad sides.
Snapshotting encourages refreshing those periodic effects when your stats are high, such as when a temporary buff procs. On the upside, there's a high amount of skill involved in maximizing that. On the downside, it's not intuitive, and the skill ceiling is so high that few can reach it without the use of specialized add-ons. To make matters worse, the benefits of maximizing periodic snapshotting is so high that it creates a balance problem. Players maximizing periodic snapshotting (primarily through the use of add-ons) do drastically more damage than intended. If we balance around taking full advantage of snapshotting, then the players who aren't doing so would fall unacceptably far behind in damage output.
Ultimately, we've decided that snapshotting isn't a productive mechanic for the game. The vast majority of periodic effects in the game that snapshotted no longer do so. The only exceptions are ones that do damage based on a percentage of a previous ability's damage (such as the Ignite from a Fire Mage's Fireball, or the periodic damage on a Windwalker Monk's Blackout Kick), as they inherently act as a delayed damage multiplier to those abilities.Temporary effects which buff the damage or healing of other spells specifically will continue to do so for their lifetime; for example, Unleash Flame (which increases the damage of the shaman's next fire spell by 40%), when used on a Flame Shock, will continue to increase the damage of the periodic effect for its entire lifetime, despite being consumed when the Flame Shock is cast. We still of course want skills and their use to embody interesting choices, and intelligent and skillful use of abilities.
- Periodic damage and healing effects now dynamically recalculate their damage, healing, Critical chance, multipliers, and period on every tick.
Skilled players will still be able to take advantage of temporary power buffs like trinket procs, and you'll still want to cast your hardest hitting spells within those proc durations. The benefits just won't extend outside the trinket procs' duration. As such, this high-skill gameplay is there, it's just rewarded more consistently. For example, a Priest's trinket procs and an already active Shadow Word: Pain will begin dealing more damage the instant the proc effect occurs, but will return to normal when the proc duration ends. Skilled players will be able to play within these proc durations to maximize effect, but it won't be as detrimental to output to anyone who isn't actively and skillfully using them to their full extent.
We also made another change to periodic effects. Haste has long affected the tick rate of periodic effects, and their duration has been rounded to whole numbers of ticks, in order to mostly preserve the original duration of the spell. This lead to Haste breakpoints where having specific amounts of Haste would cause certain periodic effects to gain an extra tick. Part of gearing your character involved trying to reach those Haste breakpoints, but not go over by too much. This was a fairly tedious number to manage, which was again mostly handled by add-ons and guides. With some new tech we're now able to calculate the effect of Haste on tick time dynamically. Any fraction of a full period left at the end of an effect will do a tick of damage or healing in proportion to the remaining time. In other words, there are no more Haste breakpoints; Haste now smoothly and accurately affects periodic effects for the entire duration.
This also opened up the opportunity to revise how we handle refreshing periodic effects. For the vast majority of spells and abilities, we had a standard rule that any refresh would add the new cast's duration after the next tick of the existing effect. In simpler terms, you can refresh anywhere between the last and second-to-last tick of a DoT or HoT with no loss. Warlocks had a special passive that changed this logic to allow refreshing with no loss anywhere in the last 50% of a DoT. We liked the flexibility that this provided; though felt it was a bit too powerful. No longer tied to whole tick times, we chose to extend the mechanic that Warlocks had to all classes, but reduce it to 30%. Everyone can now refresh their periodic effects anywhere in the last 30% of the duration for full benefit, and no lost tick time.
- Recasting periodic damage over time and healing over time effects that are already on the target now extends those effects to up to 130% of the normal duration of the effect.
DoTs and HoTs have become a slightly complex game of managing two things -- timers and numbers. Haste breakthrough points are carefully calculated via addons or websites that offer helpful suggestions for reforging. If you juggle your cards and cooldowns right, casting DoTs or HoTs when you have the most ideal cooldowns up and running results in a major boost to either damage or healing -- but you have to keep track of your buffs and debuffs.
In addition to this is the pesky problem of clipping -- re-casting a DoT or a HoT while one is still active on the target. Doing so now results, for many classes, in the new DoT simply overwriting the old one, which means that valuable ticks of damage or healing have simply been lost. Timer tracking addons help to avoid this problem, but you have to watch those timers and re-cast your DoT at a precise moment to avoid clipping, and still pump out the optimal amount of damage or healing you can do in the time that you have.
Some players have eagerly embraced this little game within a game and managed to flawlessly execute the most optimal rotation to take advantage of every little boost they can get. Others have little patience for the frustration of watching timers, buffs, debuffs, and paying attention to stats like haste on top of important things like moving out of fire or remembering where to stack during a particular phase of an encounter. That's why the changes listed above are being made.
DoTs and HoTs will no longer "snapshot," with the exception of spells that do damage based on a percentage of a previous ability's damage. Haste is now going to work dynamically with DoTs and HoTs, making haste breakthrough points a thing of the past. As for clipping, the rigid structure of this process is being relaxed just a little bit -- re-casting a DoT or a HoT anywhere in the last 30% of the previous DoT's duration will simply refresh the DoT for 130% duration -- meaning you don't lose any precious spell ticks due to refreshing too quickly.
What does that mean for the everyday player? It means you don't need to glue yourself to your spell timers quite so much anymore, nor do you need to depend on addons so heavily for optimal performance. Essentially, the developers have gone through and streamlined periodic effects and how they work for Warlords
into an elegant solution that should require a lot less tracking, and a lot more paying attention to the world around you, and having fun with that world.