Why are Thermal shields aggro-magnets?

For the caster?

My husband and I have both experienced this. At first, we thought it was just a fluke - my petless Demon/Thermal MM plays in a trio with my husband and our friend, a Stalker and a Blaster. Without fail, any ambushes target me, and anything that has insufficient damage done to it by either of the other characters aggs right to me. Aggravating, but since I chose not to take pets to take the brunt of the aggro, I kinda wrote off the fact that yeah, I die a lot on that character right now (she's 22, no IOs, etc)

My husband just started playing his Fire/Thermal Corruptor with the buddy and I on random duos. Tonight it was my Emp defender and a tri-form PB who was often in tank form. Again, without fail, ambushes targetted the Thermal, loose aggro went right to him, and the PB had to taunt a lot to keep him alive. This made One Good Spider not a lot of fun.

After the buddy logged, I got my Kin/Will scrapper (no taunt, but RTTC usually does a good job of gathering up aggro) and we did One Good Spider again because the scrapper needed her Hero Merit and the hubby needed the xp. Again, without fail, he got all the aggro from ambushes - to the point I was literally running around the map HURTING the mobs and they would continue to chase him. At one point, my fire shields wore off - and THEN the mobs suddenly noticed me.

Has anyone else noticed that Thermal seems to be Wi Flagged?

Murphy's Law of Combat: Your enemy will always attack where you're weakest.

More seriously I haven't noticed any specific tendency for ambushes to go for squishy characters over melee characters.

I have a Demon/Therm MM that actually has the Presence pool. I designed him speficially to play different from my Bots/Dark whose solo strategy is to TP team into the middle of groups and let the pets go while I DeBuff/keep healed- or in teams to DeBuff and aggro with pets. I wanted to take full advantage of the Follow>Defensive Protocals on pets and get all the aggro while my pets tore things up. My Bots/Dark is 50, while the Dem/Therm is in the 20's currently.

Converse to your information, he doesn't hold aggro well against a Brute with or without taunt (though it's always had a damage aura) which means unless I flag the pets to attack a target, they don't do much (Defensive pets tend to only attack targets that attack you or them). This won't be a problem as a lot of things have AoE's later but...

It's kinda frustrating, as I built him to start with a Taunt to get the pets going while they attacked me, and keep them healed while I took a minimal ammount of damage (Yes I plan to get the Fighting Pool and other damage mitigating powers as part of the build). This works okay when soloing but converse to your data I have a hard time keeping aggro even with the Pool Taunt in teams; particulary those with something that either can Taunt or has an aggro aura. Your Wi flag could actualy explain that, assuming I had a low initial rating, so I don't know if this can help confirm or refute your collected data.

If there's any GM's or Dev's looking into this, my character's Hellion Hound on Champion Server if that makes any difference. I hope it helps!

If I read the OP correctly, you are arguing that thermal shields draw aggro to the shielded character, not the Thermal. I have played a Thermal mastermind on and off since Going Rogue released, and I have not noticed what you're describing. He and his teammates seem to get attacked no more or less than any other character. His pets, which are almost always shielded, don't get targeted by ambushes or otherwise draw aggro in an unusual way, either.

I've also teamed with a (petless) demon/thermal mastermind while playing my stalker, and there, I had some trouble keeping the thermal alive, due to stalkers' tendency to shed aggro even when firing off AoE's frequently, as well as the frequent DoT and debuffs of her whip attacks. Damage over time and (especially) debuffs seem to do odd things to enemy AI, causing them to run in and out of melee, run across the map, change targets to the debuffer, etc.

In a mechanical sense, I'm not sure the system allows for a character to build aggro based on what buffs it is carrying. All existing forms of aggro I can think of are based on a particular target's actions (normally, some form of attack). The closest thing I can think of is the (unused) "heal aggro" setting, but that would cause enemies to attack the healer, not the healee.

I'm not completely sure if I've understood your post correctly - because you first say "for the caster" then you say you swapped toons and the phenomenon still occurred.

But my 2nd fave char is an Earth/Thermal and I've never experienced this - either undue aggro on myself having cast shields, nor have I noticed (or ever had complaints) that those I shield get more aggro.

I'm not able to find the exact detail myself but I believe that MM's draw twice as much attention as all other ATs, so maybe that's a factor

"You got to dig it to dig it, you dig?"
Thelonious Monk

I noticed this recently too. On my ss/fa brute and teaming with a friend who wanted to try a /therm I had to chase after the spawns a couple of times to get some aggro. I put it down to the x8 diff but I will do some experimenting tonight.

Heals and buffs aren't coded to generate aggro, but there is an AI script that will attack a healer/buffer preferentially.

I think each AT is assigned a "threat" level. Tanker, Brutes, MM, I guessing each have a higher threat value.
I'm not at my gaming rig, so I can't provide a screen shot, but if you enable Combat Attributes in game, I believe the value can be found near stealth.

Ok I have noticed in AE while duo-ing that occasionally all the members of a spawn will stack on the rear person instead of splitting equally. It could be related to the out-of-zone issue.