My take on AP/JHP dilemma

Unlimited party, improved damage formula, better healing system, comprehensive highlighting and more.
User avatar
Magus
Site Admin
Posts: 474
Joined: Mon Nov 21, 2016 9:13 am
Contact:

My take on AP/JHP dilemma

Post by Magus »

Probably only a very lazy person hasn't taken a shot at this by now... and here I am, overcoming my laziness.
(If you don't want to read the long-winded version, scroll to the bottom to see what this does and how to try it).

First, to address the inevitable question - why make yet yet another ammo mod? Without going into details and making it sound like I badmouth various mods or authors - none of them were to my satisfaction. Some use original formula, which, after some research, I deemed broken beyond redemption, no amount of proto modding is going to change that. Some use formulas which I find convoluted, unintuitive and unjustified. Some change too much in addition to ammo stats, and don't really achieve the desired effect anyway.
Note, however, that sfall was not as advanced at the times when the well-known ammo mods were made as it is now, and formulas might have not been researched just as well, so this attempt wouldn't even be possible without the massive amount of work that other people put into this.

OK, enough with pleasantries, to the subject. The goal was to achieve a state in which AP/JHP situation would be somewhat resolved, with minimal amount of changes to game protos and affecting gameplay much. At least in the first half of the game. Later stages are going to be affected, because that's where AP ammo is supposed to be used. Basically, same old F2, just... making sense.

Main idea.
There are two problems resulting in F2's ammo mess:
1) DT can't be affected (this has been noted and to some point addressed in some mods).
2) Ammo stats - AC mod, DR mod, and DMG multiplier are pulled out of ass. Literally, they are just assigned on basis of "this is a hi-end rifle, so its ammo is better". This is where I took issue.

If you think about it a little, penetration and dealing damage are not independent qualities. In fact, they are exact opposites. A JHP bullet does more damage because it penetrates less.

It possible to make up some special bullet that penetrates first, and after wasting a specific amount of energy, just enough to penetrate armor, mushrooms and deals damage like JHP, but then if the armor got just a little bit harder, it would be ineffective similary to normal JHP, resulting in some non-linear effects. Let's just say that we don't need combat that complicated in F2.

Thus, the idea: having multiple modifiers for ammo is not justified. A bullet is a dumb projectile, a piece of metal flying at you at high velocity. Its penetration and damage dealing capabilities are inherently inverse.
So, instead of trying to juggle multiple ammo stats against multiple armor stats, I decided to make ammo have one parameter, determining all of its properties, and... let it balance itself, more or less.

To change as little as possible, vanilla DR mod was chosen to be this parameter. Only now it multiplies both target DR and DT, and determines damage mod. And DT is applied first, not last.
The short version of the new formula is

Code: Select all

(rnd + ranged_bonus - dt) * ammo_mult * critical_mult * difficulty_mult * dr_mult
Where

Code: Select all

dt = target_dt*(100+dr_mod)/100
ammo_mult = (100+dr_mod)/100
dr_mult = (100 - final_dr)/100 //see below
final_dr = target_dr * (100 + dr_mod) / 100
As you maybe can see from that, a JHP bullet with +35% DR mod will do exactly 135% damage to an unarmored target. And an AP bullet will do 65%. Twice less, about the same relation as in the original I think.
However, as armor gets harder, JHP damage values diminish at rates far greater than AP's, and if you take someone in Power Armor, their DT alone will skyrocket to 15*1.35=20. It means that almost no conventional weapon will be able to hurt them, at least with JHP.

The exact formula is more complicated, you can review it yourself. However, I kept true to the original F2 calculations, such as total dr is capped at 90% no matter what modifiers there are, critical bypass reduces both DT and DR to 20% of their values, values can't go negative, etc.

Now, the main question - what's the result? I been using it for a while, and I would say it's more or less satisfactory. Generally I can look at the numbers and say "yeah, it make sense". And I only had to adjust 3 protos to fit the formula - 2 rockets and needler AP ammo.

This is not all, however. With the way the criticals are implemented in F2, and how Sniper perk works, critical bursts with JHP still would outperform AP against heavily armored targets. To address this, and to be "fair", as in "fair game" I was going to change bursts so that each bullet roll its own critical. That again proved problematic, as with Sniper, 10 Luck, Better Criticals and a minigun, you shell out 40 bullets per burst, with 20% chance per bullet to outright kill the target.
I don't like to change things just "for balance", but this is where I made a judgement call. Now each bullet in a burst (excepting the first one) rolls its own critical damage and armor bypass effect (but not other effects like knockdown or instant death), unaffected by Sniper perk. Essentially, it means that bursts no longer deliver over-the-top critical damage. They deliver stable damage, critical only means that a critical effect has been rolled.
Note, however, that when you're shooting 40 bullets point-blank, even if it's JHP, and even if the target is in Power Armor, 1-2 of these bullets likely will roll a critical and do some damage.

Lastly, all internal calculations are made in float, and only rounded at the end. The numbers are just a convention, after all. And rounding is "smart". For example, 5.3 damage has 30% chance to be rounded to 6 and 70% chance to be rounded to 5. Both these things ensure that output curves are smooth. No single extra DT point or extra 5% DR will suddenly make total minigun damage drop from 10 to 0.

Well, major changes are highlighted, so it's time to move to
Effects in game
- Early game is more or less the same, JHP ammo rules.
- By midgame, starting somewhere with Metal Armor Mark II, AP ammo becomes somewhat more effective. (This doesn't mean that JHP doesn't do damage, though. A point-blank burst from a minigun with JHP will rip most enemies in Combat Armor apart).
- Power armor with its massive DT is a game changer. It will shrug off most JHP attacks. Even AP ammo is not very effective. You'll need to penetrate (criticals), or bring heavy weaponry - or bust.

Extra notes
- This is currently applied to all firearms. HtH, melee and throwing are not affected. Maybe they will be, after some feedback is gathered.
- This is not an attempt to "balance", just to make sense. There's more to balance than just item stats. There's ammo rarity, price, equipping enemies with proper ammo and armor, making them to actually use that ammo, etc. The more you change, the more there's to change, to the point when it's easier to start making a new game. I won't go down that road.
- "Fixing" energy weapons - also not in the scope. Damage mod makes them slightly weaker against end-game armor, but it does that to all weapons.
- The whole idea of penetration vs damage does not apply to, say, flamethrower, or "smart" projectiles such as rockets. It is indeed possible to have some flamethrower fuel that's just plain better than another. However, I found default values for flamethrower in particular to work sensibly, thus they remained intact. Rockets had to be adjusted a little.
- I am open to changing stats of 5-10-15 particular ammo/weapon/armor items to fit the narrative better, but probably no more. The whole idea is to keep it close to original experience.
- AC mod is left without change. I would've applied the same logic to it, but unfortunately it's not possible with current sfall capabilities. Maybe later.

How to get it
It's available in the latest FO2tweaks release. Best news is that it's completely optional, you can install it, try, and if you don't like the result - just disable it.
Please do not PM or email me about my mods and projects. Use forums. Also, see our talk channels.
Njawl
Posts: 1
Joined: Thu Apr 23, 2020 6:46 am

Re: My take on AP/JHP dilemma

Post by Njawl »

I agree with what you're trying to do here. The different bullet types should have different effects. JHP should have little to damage against power armors (that is if that applies with realism. I don't know much about real bullet performance) since logic applies they can't punch through them. A bullet's ability to go through armor should greatly affect the chance of a critical hit. The original experience may be changed a bit but I'd say it's changed to a way it should have been. Anyone playing the game for the first time will assume JHP will be worse against armor. A greater change in the bullets would also add greater depth and strategy to the game.
User avatar
Magus
Site Admin
Posts: 474
Joined: Mon Nov 21, 2016 9:13 am
Contact:

Re: My take on AP/JHP dilemma

Post by Magus »

Njawl wrote: Thu Apr 23, 2020 7:57 am The different bullet types should have different effects. JHP should have little to damage against power armors (that is if that applies with realism. I don't know much about real bullet performance) since logic applies they can't punch through them.
Right. Although in fact, all ammo mods do that, with varying degrees of success. The novelty of FO2tweaks version is that applies "damage vs penetration" tradeoff rule, which I think makes sense and has grounds in reality.
Njawl wrote: Thu Apr 23, 2020 7:57 am A bullet's ability to go through armor should greatly affect the chance of a critical hit.
I don't know about that: don't see the logical link. (And to be clear, FO2tweaks doesn't do that).

 
Please do not PM or email me about my mods and projects. Use forums. Also, see our talk channels.
Cyrus
Posts: 59
Joined: Tue Nov 20, 2018 12:34 pm

Re: My take on AP/JHP dilemma

Post by Cyrus »

Burn I was doing some examination of the way you apply dmg multipler for ammo based on DR, and after some calculations, well look at this...


you formula takes DR and adds it to dmg multipler. So a JHP with DR +35 would do:

((base damage * 1.35) - DT ) * 0.65

JHP ammo should perform its best and with no armor. Lets assume a base damage of 10.

((10 * 1.35 ) - 0 ) * 0.65
= 8.775

This means that a JHP ammo with DR and ammo mod of 35, in its BEST CASE scenario (no armor), would give LESS damage than the weapon's base damage. exactly 87.7%.

Likewise lets calculate for the AP with -35.

10 * 0.65 * 1.0
= 6.5

This AP ammo in its best case would only start at 65% of the weapon's damage and it only goes downhill from there, although it falls less than the JHP would as armor goes up.

so the conclusion is, with the current setup, damage from guns is too low relative to the base damage.

You'd expect JHP to do a little more than the gun's base damage when facing no armor, or at least do 100% damage. Afterall what is the point if saying a guns damage is X when it can't ever meet that number.



What I recommend:

Double the AMMO mutli relative to the DR for jhp and half it for AP. So if DR is 35, then Ammo multi should be 70.

lets test for JHP: DR +35, dmg multi 70;

10 * 1.7 * 0.65
=  11.05

better, but still could be better.


test for AP: DR -35, dmg multi -17.5

10 * (1.00 - 0.175) * 1.0 = 10 * (0.825)
= 8.25

AP ammo = 82% of weapon damage against no armor.

So, no armor, with base damage of 10, your AP would do 8.25, JHP would do 11.05.


OR ---

Simply take your current format and multiply all damage by a constant.

For example original  number were:
JHP = 8.775
AP = 6.5
8.775 * 1.5 = 13.16
6.5 * 1.5 = 9.75


These number look much better in terms of staying more true to the gun's advertised damage, at least at start. Overall damage is increased and damage startoff (no armor) is more reasonable, and the effect of adding armor still will work the same. JHP will fall off alot. AP will stay up.

Now I didn't wanna get into more detailed calculations. But that's general idea.


You might wanna have a look at that.
User avatar
Magus
Site Admin
Posts: 474
Joined: Mon Nov 21, 2016 9:13 am
Contact:

Re: My take on AP/JHP dilemma

Post by Magus »

There is no AP or JHP "type". These are just arbitrary names. Therefore, there will be no different formula for them.
I agree that JHP should exceed base damage with no armor, I'll have to revisit that. However, AP starting at 0.65 is exactly how it's supposed to be.
Please do not PM or email me about my mods and projects. Use forums. Also, see our talk channels.
Cyrus
Posts: 59
Joined: Tue Nov 20, 2018 12:34 pm

Re: My take on AP/JHP dilemma

Post by Cyrus »

sure. if that's the balancing you wanna go for its fine, as long as you know implications.
User avatar
Magus
Site Admin
Posts: 474
Joined: Mon Nov 21, 2016 9:13 am
Contact:

Re: My take on AP/JHP dilemma

Post by Magus »

Where's 0.65 coming from? I think your calculation is off.
Please do not PM or email me about my mods and projects. Use forums. Also, see our talk channels.
Cyrus
Posts: 59
Joined: Tue Nov 20, 2018 12:34 pm

Re: My take on AP/JHP dilemma

Post by Cyrus »

Lets assume a no armor situation,

Your JHP ammo has a DR of +35. This always gets added to target Dr which since there is no armor is 0. So, 0 + 35 = 35 DR. So when using JHP ammo with DR of +35 you will ALWAYS have AT LEAST DR of 35%, if not more.

DR of 35 means 100% - 35% = 65% of total damage. so the JHP bullet can NEVER do more than 65% of the gun's advertised damage (excluding the damage multiplier).

even if JHP DR is +25, the same issue exists, but this time maximum damage will be 75% of original, multiplied by damage multi of bullet. so for example, 75% * 1.25 (bullet damage multi) = 93.75% (of original raw random dmg).

sorry for late response, I was busy with school.
User avatar
Magus
Site Admin
Posts: 474
Joined: Mon Nov 21, 2016 9:13 am
Contact:

Re: My take on AP/JHP dilemma

Post by Magus »

Cyrus wrote: Sat Oct 10, 2020 8:44 am Your JHP ammo has a DR of +35. This always gets added to target Dr
Nope, it doesn't. Check the formula more closely.
Please do not PM or email me about my mods and projects. Use forums. Also, see our talk channels.
Cyrus
Posts: 59
Joined: Tue Nov 20, 2018 12:34 pm

Re: My take on AP/JHP dilemma

Post by Cyrus »

Ok, right.

You are right. I forgot that your formula doesn't add the DR, it multiplies it. So indeed, a JHP of 35% at no armor does 135% damage, and AP of -35 at no armor does 65% damage (of original gun rand dmg).

Recalculating:  using AP -35, a target with 40% Dr is reduced to 26% (-14) and a target of 50% Dr is reduced to 32.5% (-17.5), and target with 70 DR is reduced to 45.5 (-24.5).

Ok, not as bad as I originally thought, but I do still think your initial AP damage is a bit too low. But that's my opinion and its your call. If you think all is good, then all is good. I thought I'd bring it to your attention.

 
Post Reply