On crafting by Fumbleweed

[:1]This thread was originally posted by Fumbleweed@Europe, additional thanks to Talamek@USWest and PrMoriarty@Europe for clarifications and corrections.
Some Notes On Crafting revisited Last update: 15/06/2007

* Still under construction, but mainly done *

The part "Determining ilvl of the input item" still needs a litte brush-up, and I've planned to add good hints around crafting I've read, but the important parts are done.

I you feel the need to make grammar notes, well, don't hesitate to make them.

Preface
The point of crafting is, plain and simply, to get good items, preferably such items that can *only* be gotten via crafting.
It's pretty easy to find out how crafting works - and on the other hand it's pretty hard to find out how crafting works. That means that it's very easy to read a crafting recipe, to put some items into the cube and to hit the "mutate"-button, but on the other hand it's rather difficult to say what the outcome can look like, and what it can't look like.
The main purpose of these notes is to give an answer to these two question.
(Although we'll approach the problem from the opposite direction as well.)
Note:
The crafting recipes can be found here: http://www.battle.net/diablo2exp/items/crafteditems.shtml

What is crafting
Crafting is a special case of item generation. In the case of Diablo an item is something that alters the statistics of a character or that gives certain abilities to a character. So in a certain sense an item is nothing but a set of certain attributes, and item generation in general and crafting in specific are about the rules how attributes are attached to items.

Pre- and suffixes
In the process of item generation we are not talking about attributes but about pre- and suffixes. Pre- and suffixes are the names of attributes: A Short Sword with the prefix "Strange" has the attribute to enhance Attack Rating by 151-300.
The problem is that not all affixes (which is a general term including both pre- and suffixes) can spawn on all items. As the list of the pre- and suffixes suggests most affixes can spawn only on certain kinds of items. "Strange", for example, can only spawn on weapons. However, things are a bit more complicated: the fact that "Strange" can only spawn on weapons doesn't mean that every crafted weapon has a chance to receive the affix "Strange".
Note:
A list of all pre- and suffixes can be found here: http://www.battle.net/diablo2exp/items/magic/

Affix levels
As the list shows each affix has a level, which is the number in brackets behind the item name. The prefix "Strange", for example, has the affix level 32. Now, what does the affix level have to do with process of crafting? Every crafted item receives a level. All affixes with a level smaller than or equal to this level can spawn on the crafted item.
The level the crafted item receives is called "affix level". Now, if we can calculate the affix level of the crafted item we can say what affixes can spawn on the crafted item and what affixes can't spawn on the crafted item.
Note:
As the list suggests certain affixes can only spawn on certain kinds of items. "Strange", for example, can only spawn on weapons. That means that it can't spawn on other item types, no matter what the affix level of the crafted item might be.

Calculating affix level
(Abbreviations: alvl = affix level, clvl = level of the character that is used for crafting, ilvl = item level of the crafted item, input ilvl = ilvl of the item that is mutated in the Horadric Cube, qlvl = quality level)
The alvl of the crafted item is calculated in three steps. First, the ilvl is calculated. Then the calculated ilvl has to undergo two checks and one possible modification. Finally, the result is used to determine the affix level.
First, we have to calculate ilvl:
(1) ilvl = int(.5 * clvl) + int(.5 * input ilvl)
The calculated ilvl has to undergo two checks and one possible modification.
If the ilvl calculated in (1) is higher than 99 than ilvl is set to 99:
(2) If ilvl > 99 then ilvl = 99
Then qlvl of the base item and the calculated ilvl are compared. The higher number is used for the further calculations:
(3) If qlvl > ilvl then ilvl = qlvl
In the final step ilvl is used to determine the alvl:
(4) If ilvl < (99 - int(qlvl / 2) then alvl = ilvl - int(qlvl / 2) else alvl = ilvl * 2 - 99|||Notes:

Remember that ilvl calculated in (1) determines as well the number of random affixes of the crafted item. To have a 100% chance for 4 affixes ilvl needs to be 71 or higher.

Here's a chart for character levels to gamble or buy at to guarantee each "tier" of number of affixes:

 min clvl to: affix # chances:
ilvl gamble buy 4 3 2 1
1-30 1 1 20% 20% 20% 40%
31-50 29-34 29 20% 20% 60%
51-70 49-54 49 20% 80%
71+ 69-74 69 100%
90 (+2) 88-93

Affix odds are 100% only at high-end of gamble level range. Must buy from Act 4 Normal vendors and beyond for second tier (gamble anywhere). Must buy in Nightmare and beyond for third tier.

Since the qlvl of rings and amulets is 1 the term int(qlvl/2) that is used in two parts of formula (4) is always 0, so the affix level of crafted rings and amulets is effectively determined by ilvl: affix lvl = ilvl = int(.5 * clvl) + int(.5 * input ilvl). In the case of rings and amulets the equation ilvl < (99 - int(qlvl / 2) is only false if ilvl = 99. Only if ilvl = 99 the "else"-part in formula (4), alvl = ilvl * 2 - 99, is used. Again, in the case of ilvl = 99 this means that affix lvl = ilvl = 99.

Example for calculating affix level
The Blood Weapon Recipe is used to craft a Berserker Axe (qlvl = 85) that was dropped by a monster in the Worldstone Tower in hell difficulty (input ilvl = 85). The character used for crafting has level 78 (clvl = 78).
First, ilvl has to be calculated: ilvl = int(.5 * 78) + int(.5 * 85) = 39 + 42 = 81.
Then it's checked if the calculated ilvl is higher than 99. This is not the case, so ilvl remains 81. But qlvl 85 is higher than ilvl 81, so the ilvl is set to 85.
In the last step we have to check if ilvl - in our example ilvl = qlvl = 85 - is smaller then 99 - int(qlvl / 2) to decide if we have to use the "then"- or the "else"-part in formula (4).
99 - int(85 / 2) = 57, and 85 < 57 is not true. Thus, we have to use the "else"-part: alvl = ilvl * 2 - 99, in our example 85 * 2 - 99 = 71.
So all pre- and suffixes with a level up to 71 can spawn on the crafted item.

Calculating ilvl for a given alvl and qlvl
What we have reached so far is that we know what happens when we craft an item, and thus we can now say what alvl the crafted item will have and which affixes can spawn.
In practice, however, we often want quite the opposite: we know what affix we want to spawn, but we don't know what clvl and input ilvl is required to get the wanted alvl.
For that purpose I have made a little Excel sheet that can be downloaded here:
http://www.schranzkind.de/crafting_calc.rar
Calculator update: 29/05/2007
The usage should be self-explanatory.
The Excel sheet is protected but has no password protection.

Crafting amulets
Usually, in the case of amulets, we want alvl 90 or higher. For that purpose, it is pretty hard to find items with an appropriate input ilvl. We can use amulets that are dropped in high level areas (input ilvl = area lvl = 85) or that are dropped by unique monsters or their minions in such areas (input ilvl = area lvl +3 = 88), but still, we need a relatively high clvl to craft alvl 90 (clvl > 95 in the first case and clvl > 91 in the second case). In practice, boss packs are often accompanied by or mixed up with normal monsters, so after the battle its hard to say which monster dropped what item, so to be sure, we often have to assume the worst case, input ilvl = 85.
An alternative to crafting dropped amulets is crafting gambled amulets. The ilvl of gambled amulets depends on the level of the character that is used for crafting: the ilvl randomly varies from clvl -5 to clvl +4. So if a character with level 90 gambles the ilvl of the item will be between 85 and 94. On that basis and formula (1) we can make statements on the probability of getting alvl 90 (clvl = level of the character that is used for both gambling and crafting):
clvl > 92: 100%
clvl 92: 90%
clvl 91: 60%
clvl 90: 50%
clvl 89: 20%
clvl 88: 10%
clvl < 88: 0%
To make sure that the crafted item has alvl = 90 at least clvl 93 is needed, although clvl 92 comes pretty close. The alternative is to use amulets that were dropped by bosses/minions with mlvl 88. But even in this case clvl 92 is needed to craft alvl = 90.

Determining qlvl of the input item
Due to Nebu's (GFrazier's) recent updates of the Arreat Summit the qlvls for all items can now be found in the Items-section:
https://www.battle.net/diablo2exp/items/
Note:

A picture of Geoff can be found here: http://www.battle.net/images/battle/diablo2exp/images/animations/bestiary/act5/reziarfg-large.jpg But actually it's a pretty old one, and due to reliable sources he looks much worse today.

|||Determining ilvl of the input item
Generally, there are three sources for input items: Monster drops, shopped items and gambled items.
- Monster Drops:
If the item was dropped by a monster the ilvl is determined by monster level, so ivl = mvl. In most cases mlvl depends on the area the monster has spawned. For normal monster: mlvl = area lvl, for Champions: mlvl = area lvl +2, for Bosses: mlvl = area lvl +3.
For several Super Unique Bosses mlvl is set by default. Area lvl can be watched up here:
http://home.ix.netcom.com/%7esrydzews/area_level_charts.pdf
For more information about mlvl please read the relevant passages in "Gta's guide to all that is items".
For the purpose of crafting I'd recommend to rely on gambled or shopped items anyway:
- Gambled items:
Ilvl of gambled items ranges from +4/-5 of clvl. So if you gamble an item with clvl 85 the ilvl of the gambled item randomly varies from 80 to 89.
- Shopped items:
Ilvls of shopped items directly depend on clvl. When the item is shopped in Hell- or Nightmare-Difficulty: ilvl =clvl +5. In Normal difficulty you can still get ilvl = clv +5 but there is a maximal ilvl set by act:
act 1: 12
act 2: 20
act 3: 28
act 4: 36
act 5: 45*

Credits
My own efforts and therefore these notes go back to the year 2004 when I tried to understand the fundamental principles of crafting. The basics were explained to me by Leelality and other users whose names I have forgotten. These explanations resulted into an attempt I have posted here in August or September 2004. Major corrections had to be made, mainly due to the replies of IgorekSF4 and gta-maloy]. My current attempt again had to undergo major changes due to the critics of Orphan. Antitrust gave me something to think about at TheAmazonBasin which lead to major corrections (again). Thus, the amount of details of item level generation that has been taken from the explanations of Svenska's Affix calculator has drastically increased. The passage about shopping was quoted from Gta's guide to all that is items. Thanks to Slaygor for bringing this point to my attention. Technomage-C01 contributed to this post as well with his grammatical corrections. Talamek contributed the "Chart For Character Levels To Gamble Or Buy At To Guarantee Each "Tier" Of Number Of Affixes". A special thanks goes to Schranzkind from dcboard for hosting the calculator. My apologies go to all who have contributed to this post and who have not been mentioned here, and to all that had to suffer from incorrect information that was previously posted here.