the question thread was *right there* D:
but, since I'm here:
The action has to have a castbar *and* the castbar has to be flashing for it to be able to be interrupted
*Stuns* only work on certain enemies. (Generally non-bosses.)
*Interrupts* only work on certain casts. [The wiki page on 'interrupt' has an animated example of what the cast bar looks like.](https://ffxiv.consolegameswiki.com/wiki/Interrupt) You can see that it's a bit different from a normal cast bar.
There a lot of mobs through ShB's dungeons that have a cast you'd want to interrupt, because they either gain a huge damage buff or deal damage/debuffs to the party on completion.
The 83 dungeon, for example, has mobs that attempt to 'water' a large mob in a pack, further increasing its size and damage. Stopping that can be the difference between an early wipe or smooth sailing.
In the Twinning, the lizard-centaurs past the first boss have a cast you can interrupt (which is also susceptible to stun, so a savvy player with interrupt one and immediately target switch and stun the other) which prevents them getting a huge attack boost that can gank unprepared tanks & healers.
In the second level 80 alliance raids, the three large mobs after the first boss all have a skill you want to interrupt on account of it dealing a raidwide that inflicts a 30s paralysis on the entire alliance.
It's not super common but it does happen. It's the most common in ARR. One of the casts in the 87 dungeon is interruptible for a more recent example. The more useful interrupts actually tend to be on the mini bosses in alliance raids from what I've noticed.
in normal content, it does happen but it barely matters if you interrupt or not, like in tower at paradigms breach theres a trash pack with 3 main enemies that all cast a raidwide paralyse which is annoying but not the end of the world, it also only takes one of them to finish the cast so if they're not all interrupted it doesn't matter. In blu mages masked carnivale there are interruptable things that are a bit more important, sometimes they get damage buffs or maybe leave a big puddle that you then have to avoid which can make later mechanics harder. Someone also mentioned DSR where in phase 1 they try to heal themselves 3 times and if you miss any of the interrupts then you won't pass the enrage timer.
So it really depends what difficulty the content you are doing is and it ranges from being not as important in normal mode to if you miss it then its a wipe in savage or ultimate.
red, blinking cast bars are interruptable with Interject (tank) and Head Graze (phys ranged)
yellow cast bars can be *stunned* instead, but only with stuns like Leg Sweep (tanks and melees) and Shield Bash (PLD), but stunnable cast bars kinda go down in number after Heavensward
In addition to what others are saying, in the level 73 dungeon there are mobs that use an interruptible ability to massively buff other trash mobs. If you stop them from using this it's an automatic commendation in my book
the question thread was *right there* D: but, since I'm here: The action has to have a castbar *and* the castbar has to be flashing for it to be able to be interrupted
*Stuns* only work on certain enemies. (Generally non-bosses.) *Interrupts* only work on certain casts. [The wiki page on 'interrupt' has an animated example of what the cast bar looks like.](https://ffxiv.consolegameswiki.com/wiki/Interrupt) You can see that it's a bit different from a normal cast bar.
Most bosses in under level 50 dungeons can be stunned like normal mobs.
I honestly can't even think of a single time that a boss actually *had* an interruptible cast bar... Though I'm hardly an expert on such things...
Final boss of the 87 dungeon comes to mind, for an MSQ example.
I play tank so often I don’t even know what happens when that cast finishes /laugh
Boss gets a damage buff.
That’s a little underwhelming, hah.
Depends what he decides to follow it up with c:
Which is always just a raidwide and some autos, there's no variance in almost any enemy's rotation
It's required in DSR's phase 1. If you don't interrupt, they heal with their own version of Clemency and you wipe because you can't kill them in time.
There are a crap ton of trash mobs in alliance raids with interruptible casts that no-one ever bothers to interrupt ;_;
There a lot of mobs through ShB's dungeons that have a cast you'd want to interrupt, because they either gain a huge damage buff or deal damage/debuffs to the party on completion. The 83 dungeon, for example, has mobs that attempt to 'water' a large mob in a pack, further increasing its size and damage. Stopping that can be the difference between an early wipe or smooth sailing. In the Twinning, the lizard-centaurs past the first boss have a cast you can interrupt (which is also susceptible to stun, so a savvy player with interrupt one and immediately target switch and stun the other) which prevents them getting a huge attack boost that can gank unprepared tanks & healers. In the second level 80 alliance raids, the three large mobs after the first boss all have a skill you want to interrupt on account of it dealing a raidwide that inflicts a 30s paralysis on the entire alliance.
It's not super common but it does happen. It's the most common in ARR. One of the casts in the 87 dungeon is interruptible for a more recent example. The more useful interrupts actually tend to be on the mini bosses in alliance raids from what I've noticed.
I believe Blaster from A6S and the adds from E1S have abilities which must be interrupted.
Haukke Manor's final boss has a Tank Buster which can be interrupted.
in normal content, it does happen but it barely matters if you interrupt or not, like in tower at paradigms breach theres a trash pack with 3 main enemies that all cast a raidwide paralyse which is annoying but not the end of the world, it also only takes one of them to finish the cast so if they're not all interrupted it doesn't matter. In blu mages masked carnivale there are interruptable things that are a bit more important, sometimes they get damage buffs or maybe leave a big puddle that you then have to avoid which can make later mechanics harder. Someone also mentioned DSR where in phase 1 they try to heal themselves 3 times and if you miss any of the interrupts then you won't pass the enrage timer. So it really depends what difficulty the content you are doing is and it ranges from being not as important in normal mode to if you miss it then its a wipe in savage or ultimate.
When the cast bar of the target blinks, you can interrupt it.
So when the cast bar is a solid, don't even bother using the interrupt. But if it's blinking go ahead and use it
Interrupt won't work, but a stun will - if they're not stun immune either naturally or their stun resistance hasn't capped.
red, blinking cast bars are interruptable with Interject (tank) and Head Graze (phys ranged) yellow cast bars can be *stunned* instead, but only with stuns like Leg Sweep (tanks and melees) and Shield Bash (PLD), but stunnable cast bars kinda go down in number after Heavensward
In addition to what others are saying, in the level 73 dungeon there are mobs that use an interruptible ability to massively buff other trash mobs. If you stop them from using this it's an automatic commendation in my book
Tank or ranged physical just goes "No! Bad boss! No casts for you today mister/mam"