RFC: Changing the near term `a`pply knife to item calculation of total material components returned

[jeremyosborne]

I've started calling "cut item up with knife" item salvaging, and I'm cleaning up the code that goes along with it.

This goes along with issue #7508 and associated pull request #7805.

As this is a work in progress, I'd like some comments on the current logic that exists in the code for determining just how many items you get back and my suggestions for a next-step change. I'd also welcome any longer term changes, as I'd like to get salvaging to be a bit more law-of-thermodynamics friendly as well as in game immersion friendly.

I've regrouped the code in my branch. Here's the basic code for determining the total number of raw components that can be salvaged from an item cut with a knife:

// total number of raw components == total volume of item
count = cut->volume();
// No skill in tailoring, get a random number between 0 and count inclusive.
// Only 1 skill in tailoring, lose between 0 and 2 items if there are more than
// two items possible.
if (p->skillLevel("tailor") == 0) {
    count = rng(0, count);
} else if (p->skillLevel("tailor") == 1 && count >= 2) {
    count -= rng(0, 2);
}
// On a roll of 3d3, if I roll higher than my dex, lose an additional
// 1 to three parts.
if (dice(3, 3) > p->dex_cur) {
    count -= rng(1, 3);
}
// If there are more than 1 possible items remaining that could be salvaged,
// there is a chance of losing material components if the item itself is damaged.
// If the item being cut is not damaged, no additional losses will be incurred.
if (count > 0) {
    float component_success_chance = std::min(std::pow(0.8, cut->damage), 1.0);
    for(int i = count; i > 0; i--) {
        if(component_success_chance < rng_float(0,1)) {
            count--;
        }
    }
}

If I understand this right:

• My reinforced pants are volume 8
• I'm fully awake, not sick, not drugged,
• I've got a dex of 9 (very likely)
• I've got my knife I started the game with and it's got not a scratch on it
• I'm always going to get 8 rags back

In the very near term I've already got the division of items up based on materials and am using a 70/30 split as Kevin suggested if and when an item is made up of more than 1 material (only 2 maximum items at the moment I'm told).

Changes that I propose in the very near term:

• Remove the current skill check against tailoring as it is, since it tops out at level 1.
• Increase the dexterity penalty from a roll of 3d3 (min 9 dex needed) to 3d4 (min 12 dex needed) but also decrease the malus from a random 1-3 to a random 0-2.
• Keep the damaged items will give back less material components.
• Salvaging (which is still apply knife to things and will be for at least a bit longer) uses fabrication skill instead of tailoring.
  • Given the in game description of fabrication this seems a better fit.

• Performing the act of salvage on something always has a percentage chance of losing an additional 1 material component to appease the gods of entropy:

  chance == between 0 and max(0.5, (10-fabskill)/5) as percentage
  // higher than 1.0 means always lose 1 component (even if that means the destruction of an item like a sock)

  • At low levels you'll almost always lose 1material component.
  • Even at high levels, 50:50 chance of losing an additional 1 item on top of all other maluses.
• Salvaging should train the fabrication skill up to level 1. Right now apply knife doesn't train any skill that I can see.

This isn't meant to nerf anything really, but it is designed to create a bit more scarcity.

[KA101]

I'm not hugely concerned about lost material from cutting fabric items: there's no shortage of 'em in the game. 50/50 shot seems kinda high but wev.

I like the concept. Will take a look at the code in due course.

[Zireael07]

I like the proposed changes.

[kevingranade]

I'm onboard with everything you suggested, really well thought out. Also consider making space for tool quality, though that probably makes more sense on the 'how long does it take' side of the equation. One volume = one 'scrap item' might be reasonable, or it might not, just sanity-check that that makes sense for all materials.

[jeremyosborne]

Thanks Kevin and Zireael07.

After playing the game last night, I'd like to make some tweaks to the formula:

• Instead of 1:1 (historical norm), take 20% off the top, round up. 11 volume == 9 potential material components salvaged.
• Tool damage is added in as another potential malus. Matches code for item being cut: no damage, no malus. (Thank you for the suggestion, it's a good one.)
• Keeping with the gaming atmosphere (fun over apathy): if the count of materials happens to be 0 after all deductions have been taken with the current formulas, make one last fabrication based flip of the coin to salvage at least (1*materialSet.size()) components (which makes multi-material objects have a chance of returning 1 of each type of material since I went with a 50:50 split to make things simpler in the short term). 20% at level 0 fabrication (10 socks == 2 rags) and top out at 70% at level 3 fabrication (10 socks == 7 rags).

[KA101]

Potentially bad example: I reuse old socks as rags fairly often IRL, so IMO saying that I can't simply slit them open seems unrealistically "game-based". ("Sorry, KA101, but you have to lose material because you weren't content with it in its current configuration.")

So losing 20% merely for wanting to convert, maybe not. Agreed that tool quality should factor in.

[jeremyosborne]

@KA101 fair. You're right. I do the same thing too, have a closet full of them right now. Perhaps I sort of want some of them to just disappear ;)

I won't make that change.

[kevingranade]

Woo #7805!