I'm posting this thread because I've seen a couple threads about how energy pistol suck (since deleted) and how ambush is useless here and there.
In ver 1.0.3 energy pistols received a buff. The single most important change is the base AP cost reduction of laser pistol from 22 to 15. Energy pistols are very strong when they crit and pathetically weak when they can't crit. So our goal here is to a) increase critical chance and b) increase critical damage bonus as high as possible. A properly build and geared energy pistol char can clear ver 1.0.3 dominating difficulty.
http://underrail.com/forums/index.php?topic=3281.msg17979#msg17979First, my build:
http://underrail.info.tm/build/?GQMNBwMKAwfCh8KHAAAAwodxADIcKFt2SzBwAAAAAAAAARkxMB5RWRZLAj4zwppaEvasion and Pickpocketing are optional. In theory it's possible to drop fatal throw and take psi empathy + premeditation and turn this into a psi energy pistol build. Or take more biology for SS drug. Or take mercantile to unlock special merchandise tier (in ver 1.0.3 special merchandise tier seems to spawn higher quality crafting component. However I don't see this being mention in the patch note - Confirmation/comment would be greatly appreciated).
At 14 DEX (using eel sandwich) a typical fight would be -> incendiary grenade to setup ambush, laser pistol crit shots @10 AP, electroshock pistol @21 AP (10AP point shot), plasma pistol @29AP (14AP point shot). Or stealth exit vent, aimed shot w/ plasma pistol obliterated your target, enter vent, rinse and repeat.
Gear (not even top tier, components used are around quality 12x ~ 13x):
Seeker goggles (crit chance +16%)
Infused rathound leather armor (crit chance +11%)
Recklessness (crit chance +7%)
Focus stim = crit chance +15%
= 49%
Laser pistol (crit chance = 6% from gun) = 55%
Plasma/Electro pistol (crit chance = 5%) = 54%
Feat
Ambush = crit chance + (20% + 0.3% * stealth skill points)
If we assume stealth skill point = 113 than crit chance = 53.9%
When you add everything up crit chance = 107.9 ~ 108.9%.
Next we have to understand and properly setup ambush. You can check your character's light level by studying your portrait. There are actually 5 different light levels:
Level 0 = completely darkness, portrait is completely dark
Level 1 = a little bit of light, portrait will flickering between darkness and light
Level 2 = some light, portrait will flickering between darkness (short time) and light (long time)
Level 3 = almost full light, portrait will occasionally dim but will stay bright most of the time
Level 4 = full light, portrait stay bright all the time
Ambush will only work if your char is at light level 0 ~ 1. It's actually very easy to confuse light level 1 with level 2 so to be safe always try to shoot from light level 0.
Similarly you can check your enemies' light level by right mouse click on them and looking at their portrait.
Next - the best way to light up your enemies is incendiary grenades. You will need a high effective throwing skill because you want the fire and light to land exactly the way you want it. I max out my throwing skill in my build for this reason. Once thrown you'll get this:
G = grenade landing spot
H = burning tile
E = empty space, nothing is happening
EEHHHEE
EHHHHHE
HHHHHHH
HHHGHHH
HHHHHHH
EHHHHHE
EEHHHEE
Burning tile will give off level 4 light up to 2 tiles away. You'll get another two tiles surrounding the area w/ various level of light (level 3 ~ 1), and than finally complete darkness. You should throw an incendiary grenade in turn base mode and learn its light locations.
If for some reason your incendiary grenade failed to light up your target you can try again on the same turn using a flare. Again you should throw a flare in turn based mode and study its light locations.
Energy pistols builds have the following weakness:
slow start and difficult early game
low accuracy
short range
fighting in small tight area where ambush is not possible
fighting in brightly lit area where ambush is not possible
enemies that are immune to critical (bladlings, and everything in mushroom forest)
Grenadier + three pointers + high grade frag/HE grenades will cover up some of these weaknesses (fighting when ambush is impossible). For early game quick tinkering + bear trap + abuse line of sight is the way to go, at least, that's how I did it. Ambush will help a bit w/ accuracy since it ignores half of ambushed enemies' evasion. For the end game I highly recommend you bring along advanced catalyzing belt, a fire/acid chem gun and a rapid smart 7.62mm Jaguar SMG in addition to your energy pistols.
I would rank energy pistol as the second weakest average tier class (the weakest being chem pistol) in reference to
http://underrail.com/forums/index.php?topic=3264.0. It climbed 2 tiers from poor tier in this patch. It's on the same tier as a crossbow build but rank much lower due to the short weapon range and low accuracy. You can also kill yourself if you are not careful w/ your electroshock pistol.
Nerd Commando posted an alternative energy pistol build focusing on AGI, PER and INT.
https://www.youtube.com/watch?v=yRf-gTw0jnc