Fallout: Robots
 

Injury Tolerance (Unliving) can be a pain.

More specifically, this Advantage makes tackling robots extremely difficult with old-fashioned kinetic based firearms.

Here's an example: you're fighting a Mr. Gutsy with a "Chinese Assault Rifle" (basically, an AK-47 derivative copy). The gun deals 5d+1 pi damage (Average of 18.5 damage, rounded down to 18), and Mr. Gutsy's IT: Unliving divides pi damage by 3. Let's ignore the fact that the DR on this thing would be substantial (12 is a conservative number). Heck, let's ignore DR period. If you give a Mr. Gutsy HP 16, then that's an average of six shots before it needs to make it's first death check.

With DR 12, you're doing 2 damage per shot, which means sixteen shots before it needs to make it's first death check.

By the way, most conventional firearms are not as powerful as the CAR, so the problem only gets more prominent when you're using pistols and submachine guns. Even a .308 sniper rifle is not much better off (average of 8 damage).

Sounds about right to me. Mr. Gutsy was always an ammo soaker best destroyed with EMP grenades.

Dont know the system so I probably cant help, do you deal extra damage or auto crit if you attack while sneaking like in the games?

The question is this: would you use the basic GURPS rules as is for a Fallout game, or modify how damage works?

Not automatically, but sneaking could allow you time to Aim/Evaluate, which raises your effective Skill, and therefore could raise your Critical Hit range from 3 up to (potentially) 6.

You can also buy Striking ST limited in situations where you are hidden, but that costs Character Points, and only works with muscle-powered weapons.

Yes the game is working as the writers intended to. Destroying what amounts to a miniature armored vehicle with a gun is not easy. Why is this a problem? Is your GM forcing you to fight this sort of enemy while denying you access to weapons that might be effective against it?

vitals, the wounding modifier substitute the one of the weapon/unliving advantage so a vitals hit get a x3
18 average damage, dr 12 (use armor piercing bullets if you have them) 6 damage x3 vitals (lets say the battery? or the processor) 18 damage....enough to force a roll, an heavy penalized one

pi++ or pi- get the same multipler(*3) on a vitals hit

Do robots have the Vitals Hit Location by default?

AP/APHC rounds deal pi- damage (assuming you're modifying standard AK ammo, that is), which fares poorly against IT: Unliving.

All characters have the vitals location by default unless they have Injury Tolerance (no vitals). They can also be struck in the brain for x4 damage or the neck for x3 (to be fair I would also give Mr. Gutsy IT: No neck).

As a character with the machine meta trait, the only ITs Mr. Gutsy gets by default are Unliving and No Blood. You could give him no vitals and no brain too, but I don't think either are appropriate.

At least in the newer games most (if not all) robots have a sensor module, targeting module or battery/power source that acts as a vital. Robo-Brains have brain crits also, if I remember correctly.

Would you expect a high powered EMP grenade to kill a Deathclaw?
Bullets don't do well against steel plate, same as piercing damage will not do a great deal of damage vs skeletons.

Sorry, I just realised there is no question in the OP.
Yes, you are correct, Injury Tolerance (Unliving) can make tackling robots extremely difficult with old-fashioned kinetic based firearms. That's what it is meant to do.