Rare item creation

[whathuh]

How are rare items created?

I have two theories:

1
first, the game chooses how many affixes it will have. Next it determines what type of affix it has (IE... cold resist any %, +Dam +AR). Then it uses the ilvl of the item to find out what the affix name will be and the corresponding value for each affix, omitting any that are too high. Repeat for the # of affixes it has.

2
The game chooses # of affixes. Then, it finds any random affix (not according to group). Repeat. If another affix with the same group number comes up, redo affix.

The reason I want to know is because imbueing/crafting at low levels can increase chances of getting what you want dramatically if the second theory is true. Otherwise, you dont even have to bother with ilvls and such.

[adeyke]

How are rare items created?

I have two theories:

1
first, the game chooses how many affixes it will have.  Next it determines what type of affix it has (IE... cold resist any %, +Dam +AR).  Then it uses the ilvl of the item to find out what the affix name will be and the corresponding value for each affix, omitting any that are too high.  Repeat for the # of affixes it has.

2
The game chooses # of affixes.  Then, it finds any random affix (not according to group).  Repeat.  If another affix with the same group number comes up, redo affix.

The reason I want to know is because imbueing/crafting at low levels can increase chances of getting what you want dramatically if the second theory is true.  Otherwise, you dont even have to bother with ilvls and such.
[right][snapback]57189[/snapback][/right]

Each affix has a rarity/weight associated with it. A rarity 2 affix would be twice as likely as a rarity 1 affix. Also, only affixes that can spawn on an item (based on the alvl and the item type) are considered.

Given this, it would seem the two methods are equivalent. In the first method, the weight of a group would just have to be the sum of the weights of all affixes in it.

However, in actuality, I believe the game first randomly decides whether something should be a prefix or suffix (50% chance of each) before deciding which specific affix it should be. There's a limit of 3 prefixes and 3 suffixes on one item, so if there are already 3 of one, the next affix must be the other.

[gta-maloy]]

Are there any restrictions that make two mods impossible to spawn on the same weapon? (except restrictions based on item qualities.)

[adeyke]

Are there any restrictions that make two mods impossible to spawn on the same weapon? (except restrictions based on item qualities.)
[right][snapback]57251[/snapback][/right]

You can't have two affixes of the same group on the same item.

[gta-maloy]]

heh, I knew that one....

so you can have the max fire, poison and 300% ed spawn with say LL, ML and max light.

That can make an Uber Warpike :ph34r:

[whathuh]

heh, I knew that one....

so you can have the max fire, poison and 300% ed spawn with say LL, ML and max light.

That can make an Uber Warpike  :ph34r:
[right][snapback]57256[/snapback][/right]

i believe you can get:
Ethereal War Pike
Cruel +300% ED
Master's +150% ED +250 AR
Shocking +1-480 Lightning Damage
Of Quickness +40% IAS
Of Restoration 1 durability/20 seconds
Of Slaughter +20 Max Damage

yeah, I think mine will beat yours up any day.

Each affix has a rarity/weight associated with it. A rarity 2 affix would be twice as likely as a rarity 1 affix. Also, only affixes that can spawn on an item (based on the alvl and the item type) are considered.

Given this, it would seem the two methods are equivalent. In the first method, the weight of a group would just have to be the sum of the weights of all affixes in it.

However, in actuality, I believe the game first randomly decides whether something should be a prefix or suffix (50% chance of each) before deciding which specific affix it should be. There's a limit of 3 prefixes and 3 suffixes on one item, so if there are already 3 of one, the next affix must be the other.

Still I don't think they are the same. The whole reason behind my question is to selectively choose what types of affixes are going to go on my items. For example:
Let's say that the jewel affixes Tin, Nickel, Rusty, Pearl, Freedom, Avarice, and Realgar. Next, I cube a jewel selectively with the 6 skull method for a new rare to give it an output Ilvl of 13, putting the maximum affix level at 13. If this jewel can ONLY get 4 of these 7 affixes, which ones would it choose? I know already that Tin and Nickel are both AR affixes in the same group and Rusty and Realgar are both in the +ed group. Realgar and Pearl are too high Alvls to spawn on my jewel, so I'm left with 5 possible affixes. Let's say that there is no limit to the number of prefixes you can have on a jewel, just that it doesnt go over 4. Tin and Nickel are both in the same group yielding a possible choice of freedom, avarice, or rusty each at 1/4 chance. If Tin and Nickel are not counted as the same group, then the probability decreases to 1/5.

It doesn't matter much to me how much the affixes are weighted.

[adeyke]

i believe you can get:
Ethereal War Pike
Cruel +300% ED
Master's +150% ED +250 AR
Shocking +1-480 Lightning Damage
Of Quickness +40% IAS
Of Restoration 1 durability/20 seconds
Of Slaughter +20 Max Damage

yeah, I think mine will beat yours up any day.
Still I don't think they are the same.  The whole reason behind my question is to selectively choose what types of affixes are going to go on my items.  For example:
Let's say that the jewel affixes Tin, Nickel, Rusty, Pearl, Freedom, Avarice, and Realgar.  Next, I cube a jewel selectively with the 6 skull method for a new rare to give it an output Ilvl of 13, putting the maximum affix level at 13.  If this jewel can ONLY get 4 of these 7 affixes, which ones would it choose?  I know already that Tin and Nickel are both AR affixes in the same group and Rusty and Realgar are both in the +ed group.  Realgar and Pearl are too high Alvls to spawn on my jewel, so I'm left with 5 possible affixes.  Let's say that there is no limit to the number of prefixes you can have on a jewel, just that it doesnt go over 4.  Tin and Nickel are both in the same group yielding a possible choice of freedom, avarice, or rusty each at 1/4 chance.  If Tin and Nickel are not counted as the same group, then the probability decreases to 1/5.

It doesn't matter much to me how much the affixes are weighted.
[right][snapback]57268[/snapback][/right]

In your hypothetical case, there'd still be Tin, Nickel, Rusty, Freedom, and Avarice:
Tin: group 110, rarity 4
Nickel: group 110, rarity 4
Rusty: group 105, rarity 4
Freedom: group 30, rarity 3
Avarice: group 21, rarity 4
Total rarity: 19

Let's temporarily ignore the distinction between between prefixes and suffixes.

Now, by the first method:

it would first pick the group:
group 110: rarity 8
group 105: rarity 4
group 30: rarity 3
group 21: rarity 4
Total rarity: 19

So the first affix, there's a 8/19 chance of group 110, a 4/19 chance of group 105, etc.

Suppose it picked group 110. In that group, there are two affixes:
Tin: rarity 4
Nickel: rarity 4
Total rarity: 8

So, given that it's group 110, there's a 4/8 = 1/2 chance of Tin and a 1/2 chance of Nickel. If we multiply the chance of getting group 110 by the chance of getting Tin given that we have group 110, we get 8/19 * 1/2 = 4/19 total chance that the first affix is Tin.

For the second one, the group 110 wouldn't be considered, so the remaining groups would be:
group 105: rarity 4
group 30: rarity 3
group 21: rarity 4
Total rarity: 11

So then group 30 (Freedom affix) has a 3/11 chance of spawning as the second affix, and so on.

With the second method

If it first chose the affix regardless of group, it'd look at this list:
Tin: rarity 4
Nickel: rarity 4
Rusty: rarity 4
Freedom: rarity 3
Avarice: rarity 4
Total rarity: 19

As before, there's a 4/19 chance of getting the Tin prefix as first affix. Suppose that one was, indeed, picked. Then it'd look at the same list again. However, if, as you said, picking an affix in a group that was already on the item resulted in trying again, it's equivalent to simply not having those affixes in the list:

Rusty: rarity 4
Freedom: rarity 3
Avarice: rarity 4
Total rarity: 11

So the probability of getting Freedom as the second affix would be 3/11. Same as before.

The two methods are equivalent.

This brings up another point, though. In your example, there were only four affix groups total. That means that, if a jewel has 4 affixes, it'll definitely have every one of them included. So, if we ignore the order of the affixes, there'd really just be two possible jewels:
Tin, Rusty, Freedom, Avarice
Nickel, Rusty, Freedom, Avarice

These two jewels would be equiprobable, since Tin and Nickel have the same weight.

If this still doesn't make sense, let me reiterate: Only those affixes that can spawn on an item are considered when an affix is picked. An affix can only spawn on the item if the alvl of the item is sufficiently high, the item type matches, and no affix of that group already exists on the item.

[whathuh]

It makes perfect sense now. I just didn't realize that the rarity of each group added together to form a higher rarity. I thought that each group had its own rarity associated with it when determining what group to choose. It, in fact, does, but by the added rarities of each of the affixes in each group.
I'm interested in where you found the rarities for these affixes though. I currently use d2data.net for its item/affix/tc database, but it didn't mention anything about rarity on anything other than unique/set items.

Another question on item creation regarding Ilvls and Alvls. I rushed my char to act 5 really fast and did anya's quest. When I got the rare claw from her, I was surprised to see that I couldn't use it. From my understanding, Alvl can not be higher than the Ilvl, and since my assassin was at level 1 when she got the claw, I assume the Ilvl would be 1. But the Clvl req on it was 4, meaning there was an Alvl of 6 or 7 on the claw. It could be like how small charms of life can spawn with an Ilvl of 1, but require a Clvl of 14, but I haven't seen any affixes like that on claws/weapons.

[adeyke]

It makes perfect sense now.  I just didn't realize that the rarity of each group added together to form a higher rarity.  I thought that each group had its own rarity associated with it when determining what group to choose.  It, in fact, does, but by the added rarities of each of the affixes in each group. 
I'm interested in where you found the rarities for these affixes though.  I currently use d2data.net for its item/affix/tc database, but it didn't mention anything about rarity on anything other than unique/set items.

To find the rarities, I looked it up in the Affic Calculator.

Another question on item creation regarding Ilvls and Alvls.  I rushed my char to act 5 really fast and did anya's quest.  When I got the rare claw from her, I was surprised to see that I couldn't use it.  From my understanding, Alvl can not be higher than the Ilvl, and since my assassin was at level 1 when she got the claw, I assume the Ilvl would be 1.  But the Clvl req on it was 4, meaning there was an Alvl of 6 or 7 on the claw.  It could be like how small charms of life can spawn with an Ilvl of 1, but require a Clvl of 14, but I haven't seen any affixes like that on claws/weapons.
[right][snapback]57312[/snapback][/right]

Your assumption is wrong. The alvl can be higher than the ilvl. Generally speaking, the alvl cannot be higher than max(qlvl, ilvl). However, even for this, there are exceptions. Some items have a magic_lvl. In these cases, the alvl will be equal to max(qlvl, ilvl) + magic_lvl (capped at 99). It so happens that all sorceress orbs have a magic_lvl of 1, so the alvl will always be max(qlvl, ilvl) + 1 for those.

The magic_lvl is also the cause of the diadem effect. Diadems have a qlvl of 86 and a magic_lvl of 18. So their alvl will always be max(86, ilvl) + 18, which is greater than or equal to 86 + 18 = 104 (though it's then capped at 99). So regardless of ilvl, the alvl will always be 99.

[Ruvanal]

A few points of clarity on this matter. This is from those that have looked at the coding of the way the game generates the affixes for the items.

For a rare item the game will select which set to generate an affix from (prefix/suffix).

Then it will build a list of those affixes that are of that type (prefix/suffix), can be used on that item type, have a level greater than or equal to the items alvl and a maxlevel that is less than or equal to the items alvl (if there is a value for this field), has a frequency greater than zero, has spawnable=1, has a version of 1 or 100 for LoD (version=1 is only for D2C and version=0 is for leagacy items prior to D2v1.07), has rare=1 AND does not have a group number equal to one that has already been applied to the item. It will then pick from these affixes based on the frequency values for the affixes in the list. This list has a maximum number of entries that it can contain (512? I forget); but this is really only of concern to modders that build very large affix tables since the games default ones are small enough to not run into this limitation.

For each succesive affix it will repeat the process by building a new list for each time that it picks an affix.

Basically the two ways of looking at it are the same, but there could arise some situations were the subtly of the difference could play a part. As such it is better to stick with knowing the way the game does actually do the process rather than possibly getting tripped up later by a misunderstanding of a minor point.

References to things like version, spawnable, rare, level, maxlevel, frequency and group are from the data fields of the files magicprefix.txt, magicsuffix.txt and automagic.txt files in the games MPQs.

[whathuh]

Then it will build a list of those affixes that are of that type (prefix/suffix), can be used on that item type, have a level greater than or equal to the items alvl and a maxlevel that is less than or equal to the items alvl (if there is a value for this field)
[right][snapback]57361[/snapback][/right]

so there is a minimum level to each affix? I'm not getting what the level and maxlevels are in this.

[adeyke]

so there is a minimum level to each affix?  I'm not getting what the level and maxlevels are in this.
[right][snapback]57383[/snapback][/right]

Almost all affixes have a minimum alvl needed to spawn. Some few affixes also have a maximum alvl.

For example, there are three grand charm resist all prefixes. If the alvl is in the range of 8-13, you can get the one that gives 3-6% resist all. If the alvl is in the range of 14-34, you can get 8-12% resist all. If the alvl is 35 or higher, you can get 13-15% resist all.

A similar thing happens with large charms. At alvl 17-33, you can get 3-5% resist all, while at alvl 34+, you can get 6-8%.

The maximum alvl for these affixes means that if you have a high-alvl charm, you can only get the highest resist all affixes, not the lower ones.

This use of the maximum alvl is also applied the max damage suffixes on grand charms and circlets.

There's another use of the maximum alvl. In earlier versions of the game, there weren't enough low-alvl affixes, so if you had a very low-alvl rare item, it might not be able to get the full 3-6 affixes. To fix this, a set of affixes that required only alvl 1 were added. However, in order to prevent the dillution of the affix pool from these, they gave them a maximum alvl.

Rares would be much better if they made gave more affixes maximum alvls.

[whathuh]

Almost all affixes have a minimum alvl needed to spawn.  Some few affixes also have a maximum alvl.

For example, there are three grand charm resist all prefixes.  If the alvl is in the range of 8-13, you can get the one that gives 3-6% resist all.  If the alvl is in the range of 14-34, you can get 8-12% resist all.  If the alvl is 35 or higher, you can get 13-15% resist all.

A similar thing happens with large charms.  At alvl 17-33, you can get 3-5% resist all, while at alvl 34+, you can get 6-8%.

The maximum alvl for these affixes means that if you have a high-alvl charm, you can only get the highest resist all affixes, not the lower ones.

This use of the maximum alvl is also applied the max damage suffixes on grand charms and circlets.

There's another use of the maximum alvl.  In earlier versions of the game, there weren't enough low-alvl affixes, so if you had a very low-alvl rare item, it might not be able to get the full 3-6 affixes.  To fix this, a set of affixes that required only alvl 1 were added.  However, in order to prevent the dillution of the affix pool from these, they gave them a maximum alvl.

Rares would be much better if they made gave more affixes maximum alvls.
[right][snapback]57387[/snapback][/right]

So this is in referance to the Of Dexterity or Of Strength Suffixes that have an alvl of 6, but if the alvl is not up to 6, then these still spawn, only at their +1 version. So at less than 6, they give +1. But at 6+, theygive +1-2. I get the "minimum" now.

I also agree that they would be much better with more of these affixes for higher levels, maybe too good. Think of each rare weapon you make having the cruel prefix if it chose the Enhanced Damage Group at or above alvl 56.

[adeyke]

I also agree that they would be much better with more of these affixes for higher levels, maybe too good.  Think of each rare weapon you make having the cruel prefix if it chose the Enhanced Damage Group at or above alvl 56.
[right][snapback]57452[/snapback][/right]

Well, you could still compromise by having some overlap in the affixes. For example, you could have it so an alvl 56+ weapon could spawn with 66-80%, 81-100%, 101-200%, or 201-300%, but not less than 66% (if it picks an affix of group 105, that is). (The affixes with ED and AR are in group 111 and thus work independently of the pure ED affixes).

Or you could just apply the maximum alvl to those affix groups where it wouldn't be overpowered. The most important affix on a weapon is usually the enhanced damage. So in order to keep good rare weapons somewhat rare, the chance of good enhanced damage might have to stay low. However, there are some affixes that aren't that useful. They might make a good weapon even better, but they won't make a bad weapon good.

For example, with a high-ED elite weapon, +20 max damage isn't going to make a huge difference. However, it's still nice to have that. OTOH, if you get only +1 max damage on a high-ED elite weapon, that's just sad. Late in the game, even an extra 20-75 fire damage isn't generally going to make a big difference, but 1-2 fire damage won't make any difference at all. An extra 30% to a resist can help boost a character in hell. However, 5% to a resist isn't really noticeable at that point.

If they only added a maximum alvl to affixes like these, you still wouldn't have a situation where every single rare is great. However, at least you wouldn't have an ethereal elite weapon with 450% ED, 250 AR, 2 sockets, 40% IAS, self-repair and... 1-2 fire damage.

[whathuh]

To find the rarities, I looked it up in the Affic Calculator. 
Your assumption is wrong.  The alvl can be higher than the ilvl.  Generally speaking, the alvl cannot be higher than max(qlvl, ilvl).
[right][snapback]57317[/snapback][/right]

I looked up on the affix calculator and found out that there is a reason for my claw having an alvl higher than my ilvl. The ilvl is still 1 on the claw, but rare weapons can't have less than a max alvl of 14. Also, an ilvl 60 war sword (dropped by normal baal) can't have the Berzerker's and Sounding prefix. For some reason, the alvl on rare weapons is much lower than the ilvl. To get an alvl of 50, you'd need it to be an ilvl of 63.

[adeyke]

I looked up on the affix calculator and found out that there is a reason for my claw having an alvl higher than my ilvl.  The ilvl is still 1 on the claw, but rare weapons can't have less than a max alvl of 14. Also, an ilvl 60 war sword (dropped by normal baal) can't have the Berzerker's and Sounding prefix.  For some reason, the alvl on rare weapons is much lower than the ilvl.  To get an alvl of 50, you'd need it to be an ilvl of 63.
[right][snapback]57502[/snapback][/right]

The alvl of an item is based on both the ilvl and the qlvl. The qlvl is a fixed value dependent on the base item. For example, war swords all have a qlvl of 27.

Suppose you want alvl 50+. Now, with a qlvl 1 item, ilvl 50+ is enough. However, if you had a qlvl 74 item, you'd need ilvl 75+ for alvl 50+. However, if you have a qlvl 75+ item, then, regardless of ilvl, it'll always be alvl 50+.

Looking at it another way:
- An item with qlvl 75+ will always have alvl 50+.
- An item with ilvl 75+ will always have alvl 50+.
- An item with both qlvl and ilvl less than 75 might still have alvl 50+, or it might not.

It's a bit confusing that way.

Download and read Ruvanal's alvl tables for more information.