TrinityCore/TrinityCore — comment on commit 5ea49613d24ad10b305891a39340155058e5a67e
File:  line 0
By Kline-:

I played retail from release until last year -- LOS will only cancel non-channeled spells. The top post quote from @Ka0z is incorrect information from WoWWiki. Read further into the same paragraph (1st one) it was pulled from:

>For example, if you are on the ground, and you begin casting Smite or any such spell on a melee mob that is in an elevated shack, when that >mob comes at you, he will cross behind pillars, most likely, and at that point your cast will be canceled.

>For channeled spells, however, the mob may not be attacked one second or another, or perhaps the effect that the spell gives (such as Mind >Flay) may not proc, but the next tick where there is no obstruction during that span, it will continue.

Only direct damage spells completely stop casting due to LOS. Channeled spells have no cast time before firing, they fire instantly, and instead persist for the length of channeling.

See the WoWWiki guide page specific to [channeling](http://www.wowwiki.com/Channeling#Differences_to_spells_with_cast_time)

>In addition, they have only one line of sight check at the cast of the spell; as soon as the spell hits the target, the caster does not need to >maintain LoS in order to keep the channel active.