[ORIGINAL QUESTION]: How do Sniper and Targetting stack for

[Mactab]

With Sniper, the chance is (10*LK)%. With targetted shots, the aiming modifier (e.g. 60% for eyes) is added to the base critical chance.

But how do these two effects stack, i.e.what happens if you aim for the eyes and have sniper?

I would assume that each roll is made independently and if at least one of them succeeds, then a crit is scored. For example, with 7 luck, aiming for the eyes, the 70% chance from sniper and the 67% chance for aiming at the eyes combine to be [1-(1-70%)(1-67%)] = 90.1%.

Does anyone know for sure?

 

[Lord Danath]

I don't know where you are getting the 60% bonus as that's not how Sniper works.

What Sniper does is make a roll against your luck, if it succeds it's a critical otherwise it's a normal shot.

It doesn't add to your critical chance at all, just upgrades those shots that pass the check.

So basically in your example of a 6 Luck char you have a 60% crit chance which replaces your normal crit chance. (you don't get to add anything to it even with all ranks of Better Criticals)

Which is why it's usually not worth to take any rank at all in Better Criticals if you're going to get Sniper and it's also why it's devastating in a char with 10 luck as it makes every shot a critical hit.

 

[Silencer]

He's getting a 60% chance of the critical from the 6 LK the upgrade roll would be made against.

I would assume that the upgrade roll is made independently of the crit roll, but whether that is before or after the other, I do not know.

Also, Better Criticals doesn't increase the crit chance, but the damage caused; More Criticals added +5% chance for the crit roll.

 

[Lord Danath]

He's getting a 60% chance of the critical from the 6 LK the upgrade roll would be made against.

I would assume that the upgrade roll is made independently of the crit roll, but whether that is before or after the other, I do not know.

Also, Better Criticals doesn't increase the crit chance, but the damage caused; More Criticals added +5% chance for the crit roll.

Yeah, I messed up the names of the perks.

Anyways the chance is set at whatever luck he has (in this case 6) there's no other roll made AFAIK just the one against the luck score.

From the Wiki description of Sniper:

You have mastered the firearm as a source of pain. With this Perk, any successful hit in combat with a ranged weapon will be upgraded to a critical hit if you also make a Luck roll. It adds another luck roll of (10*Luck). 10 LK means every hit is automatically a critical hit.

From the description apparently it adds another roll but then it says if you also pass a luck roll which as I understand it means there's no critical if you don't make that succesful roll.

You can probably test it with a char with Luck 1 and Sniper and see if you get more than 10% criticals or if it's added to the base chance.

 

[JesusC]

Tested this years ago with a low luck character who had 300% small guns. He maintained his ridiculous critical scoring despite the 10% chance for Sniper perk to activate. It seems to check both rolls (standard critical chance) and Sniper Chance as separate critical chances - if either confirms you get a critical.

As far as called shots are concerned, they are pretty much obviated with Sniper in play. Since calling the shot only adds % to the base critical roll, not your sniper roll. There is still some value in calling the shot to gain access to certain types of criticals (broken legs, blinded eyes, etc), but past that not too much. The irony of this is that it makes Sniper an ideal perk for users of big guns and fast shot pistols (the opposite of what a real sniper would use).

As far as the quality of critical, as others have said, that's all calculated independently of Sniper and More Criticals.[/spoiler]

 

[Per]

Some have asked me about Sniper and how it interacts with effects that modify your Critical Chance; specifically, the observation has been made that "Sniper and non-aimed" can produce less crits than "aimed and non-Sniper". Basically this is correct for values of Luck below 6. How I think Sniper works, and which is borne out by shooting the pariah dog a great number of times, is that it doesn't replace your usual crit chance but instead adds an independent possibility of a critical hit. If you have Luck 4 you'd normally get crits 4% of the time, with Sniper you'd increase that to 42% (40% from the perk plus 4% of the remaining cases). Using targeted shots to the eyes which increase the crit chance by 60%, you'd have a "normal" chance of 64%, going to 78% with Sniper. In the latter case you'd "only" be up 14% as compared to 38%, and expressed as a fraction of the original crit chance the difference in gain is much greater. Sniper would still add something, though, in this case roughly equivalent to three levels of More Criticals. Similarly, making aimed shots will improve your effective crit chance even if you have Sniper, though the benefit is smaller at high values of LK (12% at LK 8 and 6% at LK 9 for eye shots) and you might then be better served by the extra shot or two afforded by Fast Shot. By contrast, the benefit of More Criticals fades to insignificance even at moderate LK if you have Sniper. With Sniper and LK 10 you get crits all the time, but you can still get more damaging and/or debilitating ones by making aimed shots.

 

[Mactab]

Some have asked me about Sniper and how it interacts with effects that modify your Critical Chance; specifically, the observation has been made that "Sniper and non-aimed" can produce less crits than "aimed and non-Sniper". Basically this is correct for values of Luck below 6. How I think Sniper works, and which is borne out by shooting the pariah dog a great number of times, is that it doesn't replace your usual crit chance but instead adds an independent possibility of a critical hit. If you have Luck 4 you'd normally get crits 4% of the time, with Sniper you'd increase that to 42% (40% from the perk plus 4% of the remaining cases). Using targeted shots to the eyes which increase the crit chance by 60%, you'd have a "normal" chance of 64%, going to 78% with Sniper. In the latter case you'd "only" be up 14% as compared to 38%, and expressed as a fraction of the original crit chance the difference in gain is much greater. Sniper would still add something, though, in this case roughly equivalent to three levels of More Criticals. Similarly, making aimed shots will improve your effective crit chance even if you have Sniper, though the benefit is smaller at high values of LK (12% at LK 8 and 6% at LK 9 for eye shots) and you might then be better served by the extra shot or two afforded by Fast Shot. By contrast, the benefit of More Criticals fades to insignificance even at moderate LK if you have Sniper. With Sniper and LK 10 you get crits all the time, but you can still get more damaging and/or debilitating ones by making aimed shots.

Thanks, Per, that's what I assumed.

Though I believe it is possible that against certain enemies, you are better off with fewer, targetted shots to the eyes than more, untargetted shots. Eye criticals deal more damage and have a greater chance of piercing armor. Against heavy-armored enemies, that additional armor piercing makes a huge difference. Also, you're more likely to get an instant-kill critical, which against enemies with lots of health, will also significantly reduce the average number of attacks necessary to bring an enemy down. Or if you're trying to conserve ammo, though not much of a problem in Fallout 2 as much as the Wasteland Merc 2 mod.