[FO1] Do ammo modifiers actually work?

weirwood

First time out of the vault
So. First of all, hi folks. Good to see the Fallout community is still alive & kicking after all these years. I've recently reinstalled FO1 after a long, long time.

Now, Per's excellent FO1 guide had some interesting things to say about ammo modifiers, which, amongst other things seemed to reveal the assault rifle as an awesome weapon, and the 14mm pistol as a sucky one. I even found the formula on this board:

Dmg_:=Trunc(Dmg_w*(Dmg_mod_1/Dmg_mod_2)-DT_armor)-Trunc(Trunc(Dmg_w*(Dmg_mod_1/Dmg_mod_2)-DT_armor)*(DR_armor+DR_mod_ammo))

However, in-game, nothing of this seems to hold water. During some crude testing, both 10mm JHP and AP dealt the same damage against combat-armored Hub police (0-5), as do the double-barreled shotgun and the 14mm pistol; (both have a base damage of 12-22, against combat armor they do 5-11 damage each) The assault rifle, which supposedly has a -35 DR mod dealt whooping 2-7 dmg per shot.

One thing I have been able to confirm is that weapons with the 'Penetrate' perk, or the .223 pistol, at least, indeed ignore Damage Threshold.

It appears that whatever ammo modifiers exist in the code are simply disabled somewhere down the line.

Now, the problem I have is that my installation isn't 100% pristine. I've got the US version, which I patched to 1.1, after which I've used the semi-official 1.2 and unofficial 1.3.3 patches from TeamX.
Can anyone with an unmodded installation of FO1 confirm my findings? I don't believe it's a bug due to these unofficial patches, but I'd like to be sure.[/quote]
 
Ammo modifiers will not work in Fallout 1. Never. This is a bug in the engine of fallout.exe file. Very hard to fix.
 
Thanks for clearing that up. This doesn't seem to be well known in the community, I've never read about this anywhere. Probably since few people play Fallout 1 anymore.
 
The formula of damage calculating in FO1 is:

Code:
Dmg_:=(Dmg_w-DT_armor)-((Dmg_w-DT_armor)*DR_armor)
 
Cubik2k said:
The formula of damage calculating in FO1 is:

Code:
Dmg_:=(Dmg_w-DT_armor)-((Dmg_w-DT_armor)*DR_armor)

Well, that certainly explains why I couldn't see much difference between the 5mm ammo types. Couldn't you write that as:

Code:
Dmg_:=(Dmg_w-DT_armor)*(1-DR_armor)

Also I believe if Assault Rifle is a worthwhile weapon in Fo1 it's probably more because of lack of alternatives/relative ammo scarcity. In Fo2 it should never be used.
 
Also I believe if Assault Rifle is a worthwhile weapon in Fo1 it's probably more because of lack of alternatives/relative ammo scarcity.

The problem with the Assault Rifle in FO1 is that it's already obsolete by the time you get it, seeing how it becomes available at the same time as the combat shotgun, .223 pistol and sniper rifle.

It might be worth keeping equipped for its decent burst mode, but as a primary weapon, it sucks because of the crappy single shot damage.

Either way, should you ever update your FO1 guide, Per, the ammo issue is some pretty relevant information. You could also include that the 'penetrate' perk on the .223 power fist and ripper means these weapons ignore DT, I've tested it some more. I assume it's the same case in FO2. I've always wondered why the .223 pistol seemed to consistently outperform both the sniper rifle and RR LE, per shot, this explains it.
 
The damage formula Cubik has listed is his understanding by reverse engineering. What we need is to identify the function in the FO1 engine and analyze it; something maybe Timeslip could do, then define what should and how it could change, and change it.

If the weapons are not using a perk correctly then that would be in a seperate function, again task for Timeslip.

If weapon values are incorrect then modifying the weapons .pro file should be enough.
 
Glovz said:
The damage formula Cubik has listed is his understanding by reverse engineering. What we need is to identify the function in the FO1 engine and analyze it; something maybe Timeslip could do, then define what should and how it could change, and change it.

Some time I found those functions in engine of Fallout 1 but this was about a year ago. But if someone would like make a look at this functions I will find this for him/her ;)

Glovz, are you interesting in this matter?
 
I think this is the function in the Fallout 1 engine that deals with damage, but I do not have Fallout 1 (entire game) in order to test it - this is just an educated guess from looking at the Fallout 1 exe (from the official patch):

FALLOUT 1

Code:
0042227E  |> 8B56 04        /MOV EDX,DWORD PTR DS:[ESI+4]
00422281  |. 8B06           |MOV EAX,DWORD PTR DS:[ESI]
00422283  |. 8B5C24 18      |MOV EBX,DWORD PTR SS:[ESP+18]
00422287  |. E8 FC890400    |CALL FALLOUTW.0046AC88
0042228C  |. 01C3           |ADD EBX,EAX
0042228E  |. 8B4424 10      |MOV EAX,DWORD PTR SS:[ESP+10]
00422292  |. 0FAFD8         |IMUL EBX,EAX
00422295  |. 89DA           |MOV EDX,EBX
00422297  |. 89D8           |MOV EAX,EBX
00422299  |. C1FA 1F        |SAR EDX,1F
0042229C  |. 2BC2           |SUB EAX,EDX
0042229E  |. D1F8           |SAR EAX,1
004222A0  |. 0FAFC5         |IMUL EAX,EBP
004222A3  |. 89C2           |MOV EDX,EAX
004222A5  |. BB 64000000    |MOV EBX,64
004222AA  |. C1FA 1F        |SAR EDX,1F
004222AD  |. F7FB           |IDIV EBX
004222AF  |. 8B5424 20      |MOV EDX,DWORD PTR SS:[ESP+20]
004222B3  |. 89C3           |MOV EBX,EAX
004222B5  |. 29D3           |SUB EBX,EDX
004222B7  |. 85DB           |TEST EBX,EBX
004222B9  |. 7E 1A          |JLE SHORT FALLOUTW.004222D5
004222BB  |. 8B5424 1C      |MOV EDX,DWORD PTR SS:[ESP+1C]
004222BF  |. 0FAFD3         |IMUL EDX,EBX
004222C2  |. C74424 24 6400>|MOV DWORD PTR SS:[ESP+24],64
004222CA  |. 89D0           |MOV EAX,EDX
004222CC  |. C1FA 1F        |SAR EDX,1F
004222CF  |. F77C24 24      |IDIV DWORD PTR SS:[ESP+24]
004222D3  |. 29C3           |SUB EBX,EAX
004222D5  |> 85DB           |TEST EBX,EBX
004222D7  |. 7E 02          |JLE SHORT FALLOUTW.004222DB
004222D9  |. 011F           |ADD DWORD PTR DS:[EDI],EBX
004222DB  |> 8B4424 14      |MOV EAX,DWORD PTR SS:[ESP+14]
004222DF  |. 41             |INC ECX
004222E0  |. 39C1           |CMP ECX,EAX
004222E2  |.^7C 9A          \JL SHORT FALLOUTW.0042227E

Someone now needs to identify the values being passed in by the pointers.
 
Also I believe if Assault Rifle is a worthwhile weapon in Fo1 it's probably more because of lack of alternatives/relative ammo scarcity. In Fo2 it should never be used.

Yeah, the Assault Rifle, for a weapon, makes for fine firewood when you're trekking near Vault City... Also, the 10mm SMG is much better anyway.
 
I've done some testing and the armour class modifier (which modifies accuracy) doesn't work either.
 
I know it doesn't change the displayed chance to hit as in Fo2, but are you sure it doesn't work at all? Did you do some statistical testing?
 
CubiK2k seems to have taken a good look under the hood, he'd be most qualified to answer that. As it is, the bug seems to be for all ammo modifiers in general. It's confirmed that neither damage nor resistance modifiers work, there's no reason to believe that AC modifiers do.

The 'penetrate' perk on the .223, power fist and ripper means these weapons ignore DT.

There's a slight addendum to be made to this; it seems to hold true for most enemies, but I've got some conflicting results for Brotherhood Paladins, further complicated since it seems they might also use Hardened Power Armor instead of regular.

To wit, the Penetrate perk seems to reduce DT by 5 instead of completely ignoring it.
 
Per said:
I know it doesn't change the displayed chance to hit as in Fo2, but are you sure it doesn't work at all? Did you do some statistical testing?
Yes, it doesn't work at all. I changed AC modifier to 50 and 100 and it didn't affect the chance of hitting the enemy.
 
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