Can Someone ELI5 Spell Batching

[Nathanial-stonemaul]

It has been YEARS since I really played WoW. I did a cursory search for spell batching and saw a lot of posts saying it is important. But I am just not 100% what it is and how it is important. If I missed an explanatory post, feel free to link it! Thanks for any help you can provide!

[Loravir-aegwynn]

Spellbatching…shortly…is a “Lag” by system. That’s the most simple answer (even if it’s not 100% correct)

When you activate a skill…you send the information to the server. The server reacts in “batches”.
Means: Even if you (for example in PvP) activate your skill shortly before another player activates his…both skills are put into the same “batch”.
And because of this both actions will be executed, even if your skill was a stun and this stun should have interrupted the other player before activating his skill.

At least…I don’t like the re-creation of spell batching.

[Nathanial-stonemaul]

Thanks! Great reply, and I appreciate it.

[Rhyanna-whisperwind]

Spell Batching in Classic WoW

[Babylon-smolderthorn (Babylon)]

ELI5 is the laziest way of saying DO SOMETHING FOR ME.

[Nathanial-stonemaul]

I mean… I AM lazy.

[Eloraell-moon-guard]

@Eloraell-moon-guard

In a given multi-character encounter, spells are seen as being ‘sequenced’. The best example is two mages casting Sheep at each other. In a perfectly linear encounter, the first one to complete their spell sheeps the other, and the other Mage’s spell fails because they are a sheep.

However…

Done at large scale this can become slow and cumbersome if every single spell has to be processed one by one. Especially when you start to consider how far out spell and character interactions can reach. Imagine 100 mages standing 30 yds from each other in a line all casting sheep at the same time. If each spell was handled in a straight queue, the entire state of the world would have to be assessed one by one for each spell, adjusted by the spell, then the next spell is handled.

So servers use “batches” where the state of the world is locked, all the spells in the batch are assessed at once, and then the state of the world is updated at the end of the batch. Every spell that’s cast within the batch length is gathered up and then later spells are processed in the next batch.

In BfA, the technology has become far faster, and multi-threaded, so that they can process batches far faster (I think they said 10 milliseconds) and therefore batches can be far smaller. The shorter batches make it far more likely that only one spell in any given interaction happens per batch. This makes it far more likely that a Mage’s spell is cancelled by the Sheep cast on them at the same time.

In Vanilla, servers were slower and they were more worried about performance. Because of this they set the batch length at 400ms. That meant that a spell cast 300ms after another spell may end up in the same batch.

The mage example here is the classic illustration of the problem, because its possible that both Sheep spells occur in the same batch. Because both mages are not sheeped at the start of the batch, both of their spells successfully complete. Therefore after the batch is complete, both Mages are sheeped. Similarly two warriors charging at the same time, may end up at each other’s location instead of one being stunned.

Does that help?

Additional to this, monsters are not affected by spell batching.

[Xjum-skullcrusher]

It’s not artificial lag - MoP had spell batching.

All it does is queue the application of buffs/debuffs instead of applying them immediatly. This is what allows two players to CC one another.

The beta is laggy because they’re tinkering with layering atm.

[Kolben-icecrown (Kolben)]

The reason that people want it in PVP is that it is kind of a hidden skillcap thing.

For example, a Mage timing the use of Blink at the same time he/she believes a Warrior is going to Intercept. Timed properly both will go off if in the same batch. So the Mage will be in their new Blink position in an Intercept Stun while the Warrior will be in the Mage’s previous position.