Primary cause of T5 Divebomb failures

[Itseotle]

It's because height elevation messes with AoEs. Most AoEs have a pretty limited vertical range. And as you can see for divebombs, it doesn't take much height difference to avoid getting hit.

This is not accurate. The way this strategy works the way it does is because of the pre-determined locations that twin can appear for the dive bombs, as well as the boss's facing angle. If everyone is stacked correctly, twin appears just slightly in front of the group, targets a player for Divebombs, but since everyone is between Twintania and the wall, Twin faces the wall and dives out of bounds. When you run out of the pit to dodge, you are basically moving out in the time that the target has been selected, the Divebomb direction has been set, and you move before Divebomb is actually cast. If someone is not "behind" the spawn point of Twin, and is the target of Divebombs, then Twin will still spawn at the same location but face towards the arena and Divebomb in that direction. In this case, "dodging" it by running out of the pit will still put you in line of fire, which is why the group gets hit, and there push back angle is based on the angle between the character hit box and the Divebomb AoE line, which many times pushes players into the wall.

Chimera's another example of how it's used; it's why everyone pulls Chimera to the tree on top of the hill, so that ranged people don't have to worry about Dragon's Voice, and then you only have to worry about silencing Ram's Voice to keep melees safe (although most players nowadays only know the hill part, and don't silence Ram's Voice).

Another strategy that I wish would just stop. Pushing Chimera into the corner of the map severely limits the space you have to dodge both the (I forget the attack names) Homing Orb, the rear cleave, the frontal cleave that is more than 180°, and the Ground AOEs. If you play a melee, you'll notice that Chimera tends to stand still and cast 2-3 abilities in a queue, which if he's surrounded by crap on the floor, means DPS down time, or more complicated heals. Also, Dragon's Voice hits in a doughnut shaped circle, meaning you can easily dodge it by being in melee, but since most casters prefer not to do that, you can also dodge it by being at max casting range. Which IMO is a much better, and safer, strategy. Plus you don't have to wait forever for the tank to actually get him out of the cave, you can just pull the bastard and stab him in the eye.

No, the problem is that it's pretty damn hard to even SEE your hitbox with everyone crammed on that little space, and the margin for error is little.

What I do is get right against the wall a meter or 2 outside the group, then strafe into the group. Or just run in before everyone else :P

EDIT: I guess another way to look at it as player's dont have Hit Boxes but instead Central Hit Points, ie. the point in the exact center of your targeting ring. This is really easy to observe with large monsters, where you can dance around there central point and still get positional attack requirements off, and still be able to "see" the target as well. Five-Headed dragon and Cerberus are good examples. I often do Ifrit EX where I can stand inside Ifrit and still attack the nails in front of his face without getting hit by his breath.

Been there.
Provided that the party is even open to the idea of trying the intended method in the first place, poor situational and/or directional awareness still often causes people to eat dives.

T13 dives work the same exact way as T5 dives if you think about it. The only difference is that there is a marker to tell you when the "Diver" has descended, but you could still dodge T5 DB's the same way as T13 with a little awareness.

[KaitlynOfOz]

Also, Dragon's Voice hits in a doughnut shaped circle, meaning you can easily dodge it by being in melee, but since most casters prefer not to do that, you can also dodge it by being at max casting range.

Wait you are telling me Dragon's Voice is just Lunar Dynamo!?! Why have i never noticed this before? *mind blown* Oh i know, i've only ever seen/done the hill method.

[Viridiana]

Wait you are telling me Dragon's Voice is just Lunar Dynamo!?! Why have i never noticed this before? *mind blown* Oh i know, i've only ever seen/done the hill method.

You haven't noticed this on literally every single Chimera? I mean, there is no hill method for Cutter's Cry or Gorgimera. Also, why are we discussing dodging the voices? Just silence the things.

[synesthetic]

The way this strategy works the way it does is because of the pre-determined locations that twin can appear for the dive bombs, as well as the boss's facing angle. If everyone is stacked correctly, twin appears just slightly in front of the group, targets a player for Divebombs, but since everyone is between Twintania and the wall, Twin faces the wall and dives out of bounds.

Neat. I've never been able to see her dive to even guess at this. I take it that the pit's just been a nice coincidental landmark then. And I feel bad that I know how to Rot, but not the history behind this then. lol
But why did they flatten the arena then? I can't think of any other AoEs that could've been affected.

And for discussion's sake, wouldn't it be the same difference then if everyone started outside of the pit, and then ran into the pit at the sound? (i.e. still run to her backside, but now she's baited to dive inwards) I would figure there'd be less room for positional error, and maybe higher risk of people running into the wall itself. And it's been a long time since I've been in T5, but I recall misbaited dives knocking me backwards and sideways, into the wall.. Would a failed attempt in this scenario tend to move me away from the wall then?

[Itseotle]

But why did they flatten the arena then? I can't think of any other AoEs that could've been affected.

It was because of player attacks. From the Patch 2.2 notes:

The following issues have been addressed: An issue in “The Binding Coil of Bahamut – Turn 5” wherein, if the battle with Twintania takes place in an area where there is a steep difference in elevation, close range attacks may not be able to reach the enemy, in which case players must move in closer than normal for their attacks to hit.

And for discussion's sake, wouldn't it be the same difference then if everyone started outside of the pit, and then ran into the pit at the sound? (i.e. still run to her backside, but now she's baited to dive inwards) I would figure there'd be less room for positional error, and maybe higher risk of people running into the wall itself.

And it's been a long time since I've been in T5, but I recall misbaited dives knocking me backwards and sideways, into the wall.. Would a failed attempt in this scenario tend to move me away from the wall then?

This is because the AOE of Divebombs is actually larger than Twintania's hitbox. When a player gets hit by Divebomb, they are repelled in the opposite direction they are in relation to Twintania. So if Twin is Divebombing North, and your standing on her right (East) then you will get launched to the East, away from Twin. This is why you get repelled backwards on failed placement. If you are behind Twin, and since the Divebomb is bigger than Twin, you get hit and flung backwards. This is also why the strategy doesn't work in reverse, because players will move out of the Divebomb AoE when they run up the hill. Notice how those people who are slow to move get blasted out of the pit towards the center?

EDIT: For those people saying that spotting Twin during Divebombs is tricky, there is something here that you should play with to make it easier...

What I don't understand is why, contrary to every other battle up to T5, they didn't just add telegraphed AoE markers to the attack. That way we'd know exactly which direction it's coming from and have a far easier time dodging the thing.

I want to comment on this as well. If you look at the entirety of all the coils, you will notice that the "Gate Keepers", T5, 9, and 13, are the most demanding turns. They are done so to be more challenging because they are essentially the "Final Boss". If it were too easy, it would cheapen the experience of killing the "Final Boss". They are also there to not only test the things you have learned previously as a player, but to prepare you for the next series of coils/content.