To start this post off, I'll give a shoutout to TheCONMan for his 3 PER shotgun build.
I've played around with low perception shotgun builds with Leading Shot and Survival Instincts compensating for low accuracy and damage before, but I never had the balls to drop PER all the way down to 3.
After seeing his post, now I have, and it's glorious.
This build was played on DOMINATING and had a predictably tough time until a shotgun and Leading Shot were obtained, at which point it became fairly strong and only got more powerful from there.
The Build:
https://underrail.info/build/?HgUHAw4DBwfCoBkAAAAewqDClkAAAABfaRAPZAAtAMKgJQBHYl_CsF3ClmNQCCQoU8KDTivCh3rCncOO4quGBeKzrALit7AF37wI haven't been particularly minmaxy with the skills and the feats aren't in much of an order, but this is the general gist of the build.
Gear You Want:
Head: Seeker Goggles
Shield: Whatever you fancy, high INT means good crafting if you so please
Armour: Tactical vest (psionic) -> Ancient rathound leather -> Infused pig leather
Main Weapon: Tactical short shotgun (Vindicator preferred)
Offhand Weapon: Shotgun -> Thumper -> Refurbished Thumper
Belt: Shell strap/Grenade launcher/Large waist pack depending on necessity
Feet: Whatever tabis/striders you can muster -> Ancient rathound striders -> Infused pig striders
The main departure from the build that inspired this one is sacrificing a little CON and AGI for WIL. You could probably sacrifice more CON and get away with it, but I wanted to properly honour the true Chad base stat as much as I could.
Why this is an improvement for the way I play is that I like to have Survival Instincts and, when I get it, Fight Response active most of the time.
As my effective maximum HP will be 30/25% of the maximum total, the difference in a few points of CON and having/not having psi AIDS doesn't actually matter too much.
This is also my reason for going with Paranoia and Trigger Happy, but if you don't like to recklessly charge into combat guns blazing and instead want to leverage your massive HP pool, then they can be ignored.
At level 28 with infused pig leather armour and boots, I have a little over 700 HP anyway, which is more than enough to play with and makes staying under the 175 HP threshold actually pretty easy.
If I do heal past it, I can very easily cast electrokinetic imprint and walk over it if necessary.
And of course, if I want to, I can heal up to full health and take one hell of a beating.
Again, with my endgame armour, I had around 60% mechanical damage resistance plus around 50% mechanical damage reduction on top of that once I got down to the 25-30% health range.
In other words, I was taking 20% mechanical damage before even taking Aegis or food into account.
I also reduced mechanical damage taken even further by using ancient rathound leather gear before I got my pig leather gear.
In my opinion, having Stoicism beats having more HP as you get more bang for your buck out of each hit point.
This improves the value of healing in combat and also lessens the detrimental effects of morphine debilitation.
It also allows you to reach the mech. damage reduction cap, which leads to truly absurd damage reduction figures unobtainable without it.
It also allowed me to pump Temporal Manipulation pretty high via the WIL requirement, which gives access to all the usual cheese as well as Precognition giving a substantial bonus to dodge and evasion, further reducing damage taken on aggregate.
Despite how much I like Stoicism, however, I still spec into Sixth Shell first as damage output suffers horribly without it.
With blast cloth and high density padding on my leather armour and maxed out Evasion skill points, I took essentially no damage from non-spear melee (I took 13 damage and resisted 490 damage from a hit from the Abomination, for example) and explosions past a certain point, which was especially helpful when using the Thumper with 3 Per.
I like the Thumper because it expands my repertoire far beyond what another shotgun besides my primary weapon can, especially with regards to attacking long-range targets/enemy clusters, and it's pretty powerful in its own right.
Being able to use Fight Response to attack three times per round lategame without any temporary AP boosts has also been greatly appreciated, as your damage is predictably low even with Survival Instincts, so building up Sixth Shell stacks ASAP is a good way to counteract this. It also gives more of an allowance for the constant reloading you may end up doing with your Refurbished Thumper.
Well, I could list any number of other benefits, more AP is always good.
I'm currently at level 28 with this build and have thus left the final two feat options unfilled.
I could go for Bodybuilding and Increased Constitution to flex my massive HP pool, which is tempting, but most likely I'll go for Tempered: Electricity and Iron Will so I can finally give TC'ers and coil spiders the middle finger they so richly deserve.
One last thing of note is that a lot of feats I have chosen are down to my preference, and aside from the shotgun and tanking feats, you're pretty much free to chose whatever and still do well.
I specced into Leading Shot, but my accuracy against evasive targets was adequate even before doing so.
I can see the potential for including Last Stand into the build and speccing into its duration instead, but I personally don't like the feat, so I didn't.
Anyway, I've had a lot of fun with this build and I thought it was worth sharing.