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drop rate calculation and drop tables

Discussion in 'Archive 2.0' started by BISTABIL, Jan 1, 2019.

  1. Bistabil

    Bistabil User

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    Can someone confirm if l2wiki is up to date when it comes to mob drops.
    I am noticing significant difference between projected and actual values I am getting.
    It could be the case that I don't have all different variables (of course I don't) so let me know what is influencing drop rate.

    For start, let me make things very simple.
    Let's assume:
    a) character is killing mobs solo (outside of party)
    b) character doesn't have drop rune
    c) there is no other character damaging/debuffing or interacting with those same mobs

    1. Can we calculate average drop rate by just knowing parameters a) to c) and by using drop tables from l2wiki?

    2. Is, by any chance, LUC or some other stat affecting drop rate?

    3. What does it mean that mob has chance between n and m percent to drop the item as shown in l2wiki?
    I would expect that, when it spawns in the world, every mob is assigned with random value from n to m percent to drop that item. Is this the case? Is it more complex than simple linear distribution. Can I simplify this and say actual rate is (n + m) / 2 [%]. Probably I can't because why would developers make it as a range since it would make no difference for them to make the range disappear and say that actual rate is not a range but single value and it's (n + m) / 2 [%] since we have no way reading this rate from mob (or we have?). For us it would make no difference if developers would declare average rate instead of creating the range. Maybe I don't see some variable here. Can I then at least assume that actual rate is never bellow n%?

    5. Is l2wiki up to date when it comes to drop rates?

    6. Is there level difference penalty (actually I know there is but for sake of completeness..) and how exactly it affects drops? Please provide formula if possible.

    7. Is it possible to get multiple items dropped at the same time or one drop automatically excludes possibility to get something else from the list?

    After we clarify this, then I could ask, what happens when there are more characters involved, inside of party, outside of party, with different levels, overall damage done by these same characters, existence of runes.

    I can only assume that NC never published the formulas but I guess experienced people already worked out relations and have at least some ways to roughly estimate the rate.

    Can someone at least clarify this simpler case involving just one character?
     
  2. Palkah

    Palkah User

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    You need to take level difference between you and the monster into account.

    According to https://l2wiki.com/Dyes_and_Tattoos, LUC does have an effect on drop rate, unless it's bad translation and it works only for spoiling. Most of the issues we have with understanding the game are caused by bad translations (but that's because Korea likes to call same effect with 5 different names).

    That is a mystery. When you use a GM command on an already spawned monster, to get all the possible information, when it comes to drop rate the server reports exactly what you see in L2Wiki: a range of rates. No other rate information is provided. It does not change when you open a Rune or get level difference. It is not related to LUC because the server reported the same ranges back when I played on Lilith server, which was years before LUC was introduced as a stat. There are multiple theories explaining that.
    1. The rate is selected randomly from the range during drop calculation
    2. (ILLUMINATI CONFIRMED) There could be a system in the game that governs all drops, enchanting, opened chests and events. It's main goal is to boost the rate when not enough items are dropped, and lower it when too many are dropped.

    Now it is probably the #1, but personally I'm a huge fan of #2 because it explains a lot. It is long known that all farm events are programmed to generate a maximum of X items per hour. Fragola confirmed it. If too many items are dropped, rate decreases. This is to ensure that an event doesn't generate too many top rewards on the server. So, since they already have the system to control the rates, why not use it on everything? If you look at the history of events (incl. L2Store), you will always notice the same pattern: for some time everything is okay, and after few hours/days people start crying that "the rates were decreased", "ninja update", even though no server files regarding the events were changed. Even yesterday I noticed a cry on Discord that current event was nerfed. My theory is: every time an event happens, the real success rates are higher than programmed, because RNG is simply broken. Once that reaches a threshold, the system kicks in to nerf it, so that {Number of successes}/{Number of attempts} server-wide equals to the programmed value.

    Illuminati stuff done, for your calculations just take the average value.

    Yes, most of L2Wiki content is generated by running a script on the server files, which export the information to L2Wiki database. Whenever a file changes, script is re-run.

    There is a penalty, I don't remember what are the values after a rework some updates ago, but afaik if you are 3 or more levels higher than the monster, the penalty starts to apply. First stage is I think 15%. It's applied as the last factor. Let's say L2Wiki says you have a mob that drops an item with 70% chance. After applying all the runes and everything, it goes to let's say 140%. Then that gets rounded down to 100%. Now that final result gets multiplied by the penalty (so 15% penalty multiplies this result by 0.85, resulting in 85% chance to get this item).

    There are "drop groups". They are not marked in any way on L2Wiki. I don't remember if they are reported by the server when asked with GM command. If you look at https://l2wiki.com/Kalios_(for_party), I can tell you that EWR and EAR are in one drop group - getting one excludes the other. The chances you see next to these items (~50%) are the real chances. You would normally think that this gives 4 possibilities: no drops, EAR drops, EWR drops, and both drop. However, when you farm Kartia on proper level, you will notice that you always get either EAR or EWR, but never two at the same time (unless drop runes change something here), and never none of these (unless you have a level penalty). Drop groups are known from experience, there is no source to check them for a particular monster.

    Oh boy, I don't think even Korea knows that xD
    As for the runes - people from top clans can probably say more. AFAIK the runes in a CC are only counted for the CC leader's party. If all party members have it, the rate is increased by the value on a single rune. If only some members have it, it's [number of people with rune]/[total number of people in pt] * [value on rune]
    As for looting rights - CC that deals more damage takes the drop. This includes "reseted" damage - if you take down 90% of boss HP, reset it, take 90% again, reset, and some other party takes down 100% - the drop is yours unless there was a 10+min break between a reset and hitting the monster/boss again. This is because your group dealt more damage in terms of numbers.
    Level difference - the server checks how much damage a monster/boss was dealt before it died. Then it takes a list of top DDs, and starts from the top. It moves DDs to a second list, until their damage is more than 50% of total damage. Then only these DDs levels are checked for the level penalty, and I can be wrong here, but from what I know it takes the biggest level from the list and uses that to calculate the penalty.

    I'll see if I can experiment with the drop system, since that's actually a good topic.
     
  3. zauliuz

    zauliuz User

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  4. Bistabil

    Bistabil User

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    @Palkah
    Thanks for detailed answer.

    I've noticed another thing regarding drops.
    Their value in shop seem to be exactly a half of what is stated on wiki.
     
  5. Palkah

    Palkah User

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    This is because each item has a price assigned in server files, and in the older updates that price was used to generate Stores (Grocery, Luxury) with a script. The price in files says how much you have to pay for an item, and sell price was done the simplest way: buy price/2.