---

Q u o t e:

affix level - alvl, just as with item creation level, is a value inherent to each individual item that determines how good affixes the game could pick for the item. As I mentioned above, when an item is to have affixes (prefixes or suffixes, the game uses a relatively complex algorithm to transform the item's item creation level and the base item's quality level into a new value, or level. This new value is the one that is compared to see what affixes are possible. People writing formulas and wanting to explain this wanted a new name and abbreviation in formulas for this and apparently came up with affix level. So it is really just a modified item creation level, used to compare with the different quality levels of affixes.
-Jarulf

---

---

Q u o t e:

Item creation level or item level - ilvl, one of the most misunderstood levels and also one of the most misused and wrongly defined abbreviation I would say. The item creation level (or simply item level as many say) is a numeric value assigned to each item when it is dropped. This value is set based on the source of the item, and is used by the game to determine what magical (and non magical) properties the item can possibly have. This is usually done by either direct comparison of the quality levels of properties and the item creation level, or through various formulas and calculations that turn the item creation level and the quality level of the base item into a new value that is then compared to the quality levels of item properties (yes, confusing, but it is a bit complicated, I won’t go into detailed item creation here though).
-Jarulf

---

---

Q u o t e:

Once upon a time, the alvl determined the rlvl (rlvl = alvl * 3/4) and I think the Arreat Summit pages still say that somewhere. This has been preserved in many cases, the rlvl is defined to be whatever alvl * 3/4 (rounded down) is equal to - but it is an important distinction that that is by definition and not following a formula. The rule is broken by many affixes.

The rlvl of an item is simply the highest rlvl out of each of the affixes it has and the rlvl of the base item itself, with two exceptions, both involving the cube:
If a (rare or unique) item is upgraded it gains an rlvl penalty.
A crafted item also gains an rlvl penalty.

Rolling charms with pgems though is no different than the charm dropping.

-Thrugg

---

___________________________________

Section 1.2 - Explanation of Treasure Class or (TC)
___________________________________


Treasure Class is basically many items grouped together based on their theoretical value. Every item that can be dropped by monsters has it’s own Treasure Class.

A typical TC group will contain several items that have similar qlvls. The lowest TC possible is 3, every group following will be a multiple of 3 until the highest possible which is 90. This basic set-up is true for all TC groups containing weapons or armors. Here is an example, following is all weapons found in the TC group for weapons classified as “3”:

Short Sword, Dagger, Hand Axe, Club, Scepter, Short Staff, Wand, Short Bow, Javelin, Throwing Knife, Katar, Eagle Orb

Other items, such as gold, keys, amulets, charms, etc., will have their own TC group assigned. Every monster can be ascociated to any of these groups…of course the programmers decide this.

More complicated than item related TC groups are the groups of TCs (many TCs grouped together) which are allocated to monsters. I will not get into much detail on these groups as they are very complicated. They are basically many TCs that a specific monster is allowed to choose from. Every monster has a default group like this. For monsters that have a lower mlvl than the area lvl, this group is upgraded to allow for higher drops. Super Unique monster however use their own groups that cannot be effected by the area level. For a list of the groups held by Super Uniques, looks here:
http://www.diabloii.net/items/110monster.shtml

Many objects found throughout the game also have groups of TCs allocated to them. These work slightly differently than those allocated to monsters but they still are rather complicated and will not be explained in great detail.

An example of these groups can be seen in this next table:
 

"Chest TC"      "Equip TC"      "max item TC level"





Act 1 (H) Chest A  Act 1 (H) Equip A          63


Act 1 (H) Chest B  Act 1 (H) Equip B          66


Act 1 (H) Chest C  Act 1 (H) Equip B        66


Act 2 (H) Chest A  Act 2 (H) Equip A        69


Act 2 (H) Chest B  Act 2 (H) Equip B        69


Act 2 (H) Chest C  Act 2 (H) Equip B        69


Act 3 (H) Chest A  Act 3 (H) Equip A        72


Act 3 (H) Chest B  Act 3 (H) Equip B        75


Act 3 (H) Chest C  Act 3 (H) Equip B        75


Act 4 (H) Chest A  Act 4 (H) Equip A        78


Act 4 (H) Chest B  Act 4 (H) Equip B        78


Act 4 (H) Chest C  Act 4 (H) Equip B        78


Act 5 (H) Chest A  Act 5 (H) Equip A        84


Act 5 (H) Chest B  Act 5 (H) Equip B        87


Act 5 (H) Chest C  Act 5 (H) Equip B  87

More details can be found below.

___________________________________

Section 1.3 - Explanation of the Dimnishing Return
___________________________________

Here are the formulas used during a drop to determine what the final outcome will be. The outcome of this formula is then applied to each drop.

Uniques
MF * 250 / (MF+250)

Sets
MF * 500 / (MF+500)

Rares
MF * 600 / (MF+600)


Magic items are not affected by diminishing returns.

Although your MF is diminished towards uniques, sets, and rares, it is never worse than it previously was. When adding to the total Magic Find of your character, the UmagicFind (or uMF {unique magic find}) will always rise. This rise is based on the above formula.

 

magic/normal   rare   set   unique





200            150    143   111


400            240    222   154


600            300    273   176


800            343    308   190


1000           375    333   200


1200           400    353   207


1400           420    368   212


1600           436    381   216

Note: The Diminishing return now kicks in at 10%MF in 1.10.
.
http://stud4.tuwien.ac.at/~e9325732/images/diminishingMF.jpg


With the above information, it should be rather easy to find your balance point with Magic Find.

_________________________________________________________________

Section 1.4 - Gambling
_________________________________________________________________

This is the third installment of this section. It has been revised and a little bit has been removed from the content. Please note that this section is 1.10 based and the information has been revised by many.

How clvl is involved:

Character level determines two things while gambling, the first is what items may be purchased and the second is what item lvl the purchased item will attain.


Please visit this section of the Arreat Summit to know at what level certain items are available:
http://www.battle.net/diablo2exp/basics/gambling.shtml
(scroll down some, a large table shows the items)

Item lvls are then determined by an equation:
ilvl = clvl + rnd[10] - 5
or more simply clvl-5 through clvl+4


Odds via uniques, sets, rares


The odds to receive a specific quality are much higher than recent patches (1.09 and 1.10beta). The following are the odds for a purchased item to become unique/set/rare.

unique: 1/2000
set: 1/1000
rare: 1/10
magical: 1/~1.1

or percentages:

Uniques: 0.05%
Sets: 0.10%
Rares: 10.00%
Magic: 89.85%


Odds at attaining exceptional/elite versions of the item


Here are the equations used to determine whether or not the item will become exceptional or elite:

exceptional = 1 + (ilvl - excep qlvl) * GambleUber / 100

elite = 1 + (ilvl - elite qlvl) * GambleUltra / 100

gambleuber = 90
gambleultra = 33

One last thing I would like to add about gambling is simply this. Magic Find in no way affects gambling.

Rarity of an item may also lower your odds at a unique or set item when more than one unique or set has the same base item. Rarity will be explained further in a future section.

Section 1.5 - Diminishing no-drop chances and boss extras
_________________________________________________________________

This is where the number of people in a game make a difference.

If you are MFing from monsters and wish to up your chances a little, make/join games with more people in it. Every monster has a given chance to skip a drop (no drop) and having more people in a game reduces the odds at this happening. The change is slight but noticeable over time.

Every monster and Super Unique in the game has it’s own no drop percentage. The more people you have in game, the lower this percentage becomes. At times it’s even possible to reach a zero no drop percentage. (guaranteed six TC rolls) With a low or non-existing no drop percentage, your odds at getting that unique you’ve been looking for is slightly higher in most cases.

The Countess is the one monster that uses the no drop percentage against those looking for items from her. More on this can be found in a future section of this guide.

bosses

Certain bosses possess extra bonuses which can come in handy when MFing/GFing (gf = gold find).

Mephisto as an example can only drop items which are at least magical, and he possesses a bonus which improves the odds of rolling a unique item. Here is a very helpful quote from Thrugg that explains this in great detail:

 

---

Q u o t e:
OK, MF. As I stated, the game checks for unique/set/rare/magic in turn, and your MF is used each time. Base chance of each depends on the item type (class-specific items are more likely to be higher quality) but for regular stuff it is 1/400 unique, 1/160 set, 1/100 rare and 1/34 magic. This is modified slightly by the difference between the monster's level and the item's level (ie Hell Baal dropping a Sash is more likely to be high quality).

Your MF is applied to the chance next. However, it is put through a diminishing formula, slightly different for each test. For the unique test your effective MF is MF * 250 / (MF+250). This is capped above at 250 no matter how high your MF gets. Your 215% becomes 115% after diminshing, which means an item is 2.15 times as likely to drop unique, or about 1/186 of the time. For sets, the formula uses 500 instead of 250. For rares, 600. For magic, it is not diminished at all, so you do have 3.15 times the chance of an item dropping magic, or about 1/11.

Next you apply boss bonuses. Random uniques, fixed uniques and particularly act bosses get a further improvement to their quality chance here. For example, Mephisto is 1024/41 times as likely to drop a unique, set or rare as a regular monster, and always drops at least magical. That brings your chance of getting a unique from Meph up to a healthy 1/7 or so - just about one every time you kill him. It doesn't take too long to fill up your stash running Meph.

There are some details I have omitted for simplicity, but that is probably enough to get you going.

---

Other uniques such as the council receive bonuses for gold drop as well. These become handy for those who wish to often repair expensive items or for those who gamble regularly.

_________________________________________________

Section 1.6 – Object drops and an in-depth look at special chests
_________________________________________________

The only relevant information I can dish out when objects are involved, has been dished out by Jarulf in the Lurker Lounge awhile back. Here is his post:
http://www.lurkerlounge.com/forums/index.php?showtopic=3112&hl=

A few highlights from that link:
-Goo piles from the Maggot Lair have a 33% chance to set off trap #3.
-Normal chests and objects can drop up to 4 items. (not including special chests)
-Chests with no desired quality allow MF to be applied.
As requested by certain people, here is an explanation of the Special chest drop. Quoted below is the original text written by Jarulf over at the Lurker Lounge forums:

 

---

Q u o t e:
First, the sparkling chests, the most complex one. There are 6 different options with the chance of being picked as below.

1. 2% chance
2. 4% chance
3. 6% chance
4. 20% chance
5. 30% chance
6. 38% chance

Note that the last option is also what I call the "fail" option. That is, for many of the other cases, if some requirement has not been fulfilled with the drops done, there will be additional drop according to option 6.


1. The game will make a chest TC drop with a desired quality of unique. If the drop fail for a magical+ test, it will make another chest TC drop with a desired quality of unique. If that drop also fails for a magical+ test, the game will also make a drop according to option 6. Note that a chest TC drop can still generate, say 3 unique items for each of the two attempts and yet fail, as long as the first item in those two attempts were items that can't be magical.

2. The game will make a chest TC drop with a desired quality of set. If the drop fail for a magical+ test, it will make another chest TC drop with a desired quality of set. If that drop also fails for a magical+ test, the game will also make a drop according to option 6.

3. The game will make a chest TC drop with a desired quality of rare. If the drop fails for a magical+ test, it will make another chest TC drop with a desired quality of rare. If that drop also fails for a magical+ test, the game will also make a drop according to option 6.

4. The game will make up to 10 chest TC drops with a desired quality of magic. As soon as 3 of them pass a magical+ test, the 10 attempts are aborted.

5. The game will make up to 10 chest TC drops with a desired quality of magic. As soon as 2 of them pass a magical+ test, the 10 attempts are aborted. It will then drop a number of gold piles equalling 7 minus the numbers of failed magical+ attempts done so far.

6. The game will make up to 10 chest TC drops with a desired quality of magic. As soon as 1 of them pass a magical+ test, the 10 attempts are aborted. It will make a number of chest TC drops with no desired quality (thus normal quality probabilities including MF occurs) equalling 4 minus the numbers of failed magical+ attempts done so far. Next it makes 5 gold drops, 2 heal potion drops and 2 mana potion drops.

Phew

-Jarulf
original text:
http://www.lurkerlounge.com/forums/index.php?showtopic=3112&hl=
 

---

I shall rip her apart:

 

---

Q u o t e:

First, the sparkling chests, the most complex one. There are 6 different options with the chance of being picked as below.

1. 2% chance
2. 4% chance
3. 6% chance
4. 20% chance
5. 30% chance
6. 38% chance
 

---

This section is pretty simple. Regardless of whether or not your chest is sparkly, locked, unlocked, or normal, a special chest will always have these exact chances at each field. (by field I mean any number from 1-6)

 

---

Q u o t e:

Note that the last option is also what I call the "fail" option. That is, for many of the other cases, if some requirement has not been fulfilled with the drops done, there will be additional drop according to option 6.
 

---

This was written simply to place enthusiasm on the fact that no matter what happens, you will receive a minimum drop. This drop will be focused on in the sixth step.

 

---

Q u o t e:

1. The game will make a chest TC drop with a desired quality of unique. If the drop fails for a magical+ test, it will make another chest TC drop with a desired quality of unique. If that drop also fails for a magical+ test, the game will also make a drop according to option 6. Note that a chest TC drop can still generate, say 3 unique items for each of the two attempts and yet fail, as long as the first item in those two attempts were items that can't be magical.
 

---

This basically explains in small detail how the game decides what will drop. First, the item will be randomly selected. If this item drops as a unique, then nothing else shall happen. If it doesn't drop as a unique, the item will fall magical and another item will be selected to drop. Once again, if this second item is unique, you will receive a two item drop. The first failed unique and this successful one. If this second item were to fail, the first field is then aborted and the sixth field comes into play. More on this in the sixth section.

 

---

Q u o t e:

2. The game will make a chest TC drop with a desired quality of set. If the drop fails for a magical+ test, it will make another chest TC drop with a desired quality of set. If that drop also fails for a magical+ test, the game will also make a drop according to option 6.
 

---

Like the unique explanation above, you have two chances at a set item. If your two chances fail, you'll receive the two items as magical and field six will kick-in.

 

---

Q u o t e:

3. The game will make a chest TC drop with a desired quality of rare. If the drop fails for a magical+ test, it will make another chest TC drop with a desired quality of rare. If that drop also fails for a magical+ test, the game will also make a drop according to option 6.
 

---

Same as above.

 

---

Q u o t e:

4. The game will make up to 10 chest TC drops with a desired quality of magic. As soon as 3 of them pass a magical+ test, the 10 attempts are aborted.
 

---

Here the game can drop up to 10 items. If none end up as magical quality, field six will kick-in. As soon as three magical items drop, you move to field six. It is very likely for the first three items to drop as magical.

 

---

Q u o t e:

5. The game will make up to 10 chest TC drops with a desired quality of magic. As soon as 2 of them pass a magical+ test, the 10 attempts are aborted. It will then drop a number of gold piles equalling 7 minus the numbers of failed magical+ attempts done so far.
 

---

This is the same as the fourth field, you only get two magical items as a max here though.

 

---

Q u o t e:

6. The game will make up to 10 chest TC drops with a desired quality of magic. As soon as 1 of them pass a magical+ test, the 10 attempts are aborted. It will make a number of chest TC drops with no desired quality (thus normal quality probabilities including MF occurs) equalling 4 minus the numbers of failed magical+ attempts done so far.
 

---

I have split up the sixth section because three main things will happen here. First, you will receive up to 40 items with only one able to be "magical+"**. depending on how many were dropped in the last few steps (if applicable). Once one item passes the test, we move on to the following:


 

---

Q u o t e:

Next it makes 5 gold drops, 2 heal potion drops and 2 mana potion drops.
 

---

Regardless of the outcome of all fields selected, you will always receive at the very least one magical item, four normal items, five gold drops, two heal potions and two mana potions.


**magical+ is a test done in accordance to the "desired quality". If the "desired quality" is magical, a magical, rare, set or unique drop will count as a successful drop. If the "desired quality" is unique, only a unique will succeed the drop.

Now that you guys are familiar with how chests and objects think, here is a little more info to bash into your heads:



 

"Chest TC"      "Equip TC"      "max item TC level"





Act 1 (H) Chest A  Act 1 (H) Equip A          63


Act 1 (H) Chest B  Act 1 (H) Equip B          66


Act 1 (H) Chest C  Act 1 (H) Equip B        66


Act 2 (H) Chest A  Act 2 (H) Equip A        69


Act 2 (H) Chest B  Act 2 (H) Equip B        69


Act 2 (H) Chest C  Act 2 (H) Equip B        69


Act 3 (H) Chest A  Act 3 (H) Equip A        72


Act 3 (H) Chest B  Act 3 (H) Equip B        75


Act 3 (H) Chest C  Act 3 (H) Equip B        75


Act 4 (H) Chest A  Act 4 (H) Equip A        78


Act 4 (H) Chest B  Act 4 (H) Equip B        78


Act 4 (H) Chest C  Act 4 (H) Equip B        78


Act 5 (H) Chest A  Act 5 (H) Equip A        84


Act 5 (H) Chest B  Act 5 (H) Equip B        87


Act 5 (H) Chest C  Act 5 (H) Equip B        87

The above table shows you the corresponding TC groups that those chests can drop (runes are excluded).

This next table shows you the possible rune drops based on the near end acts. Previous acts don’t drop high enough to mention:

Act 5 (H) Good - Zod
Act 4 (H) Good - Cham
Act 3 (H) Good - Ber
Act 2 (H) Good - Lo
Act 1 (H) Good - Vex
Act 5 (N) Good - Ist
Act 4 (N) Good – Um

”good” TCs are used for rune selection. For monsters they are equal to the following:

 

---

Q u o t e:

mlvl TC Rune
66 66 Vex
69 69 Lo
74 72 Ber
75 75 Ber *
78 78 Cham *
81 84 Zod *
83 87 Zod

The * means that melee (hand-to-hand) monsters actually need to be one level higher to reach that drop breakpoint, eg a melee monster needs to be mlvl 76 to drop TC75.

-Thrugg
 

---

____________________________________

Section 1.7 – Item Generation
____________________________________

I’m simply going to state in which order an item is generated from monster kill to drop. The rest of the information can be found scattered everywhere in this thread as well as here:
http://www.diabloii.net/items/item-generation.shtml
(Note that some of the information in this link is 1.09 or 1.10 beta based. For example, the corrected diminishing returns chart in this thread in comparison to the old one linked.)

Right after killing a monster or activating/opening an object, the game checks for an item drop. More specifically it checks to see if the “no drop” is true. Once an item has been selected, the treasure class then comes into play. This step is skipped for objects that have a desired quality, or is somewhat modified in some cases.

Treasure class (TC) is selected as soon as an item is able to drop. Every treasure class that can be dropped by the monster or object killed/activated will have a set percentage to be selected. Certain TCs are much less likely to drop then others, specifically class specific, “good” (used for runes) and higher numbered weapon and armor TCs.

If a treasure class with items that have multiple qualities (unique, set, rare, etc.) is chosen, then your Magic Find (MF) is used to help determine what quality will be chosen. Using the Diminishing return formulas, you can figure out for yourself how much better your odds will be for certain items. Or use a calculator like the one imbedded in the ATMA program. The item’s quality will be checked in this order:

(Unique > Set > Rare > Magical)* > Superior > Normal > Low**

*Areas in brackets are the only sections effected by Magic Find.
**Bosses cannot drop normal quality if a magical+ version exists. Certain quest only kills (Mephisto) cannot drop less than rare as quality.

After the quality is chosen, an ethereal check is done. Though your odds at an ethereal item isn’t very high (near 3%), it does happen often enough to be noticed. Items with the indestructible mod cannot spawn as an ethereal item. Only items that are forced to drop as ethereal (ethereal edge) or that have been zodded can have both the ethereal and indestructible qualities. (bugs not included)

If a unique or set quality of an item is chosen but the monster’s level is not high enough to allow a drop (the qlvl is then higher then the mlvl) a “failed item replacement” will then be selected to replace the unique or set. For uniques, a rare item of the same type will be selected with triple it’s normal durability. For sets, a magical item of the same type will be selected with double it’s normal durability. If the item is a stacked item (javs, throwing weaps), the extra durability will still be there, even if it’s not listed.

Sockets, affixes and the rest will not be explained here as they do not follow the main topic. The link above and this next link will tell you all you need to know, if you are interested:
http://www.battle.net/forums/thread.aspx?fn=d2-gameplay&t=116343&p=1&tmp=1#new116343

________________________________

Section 1.8 - Magic Finding Blizzard Sorceress
________________________________

This guide is being hosted over here:

http://www.theamazonbasin.com/d2/forums/index.php?showtopic=55046

________________________________

Section 1.9 – Rarity
________________________________

Rarity, a word many people that play Diablo never really came across.

What is rarity? Well it’s a number associated with an item. This number is then used to decide on the probability of any given drop when more than one of the same item type is present.

What does that mean? Let’s use an example so that you all can equally understand this allocation:

You’re killing a monster in Nightmare act 2. This monster has an mlvl that will only allow the first three rings in the unique ring group. A unique ring drops. At this point you see the ring but do not know which it is. Well, rarity helped in the decision. Since Manald, Nagel and the SoJ are the only rings that were possible, your machine had to choose which one of these actually gets to drop. A Nagel ring has a rarity of 15, Manald has a rarity of 15 and the SoJ has a rarity of 1. If you would like to know the odds for any given ring, simply add them all together and divide your chosen ring by the total number. Example:

You want a SoJ (who doesn’t):
15+15+1 = 31
1/31 are your odds for this ring.

You want a Nagel:
15+15+1 = 31
15/31 are your odds here. In this case, the same result will be true for the manald ring.

You must also keep monster levels in mind while trying to figure this out. Andariel in Nightmare has an Mlvl of 49. This is why only those three rings can drop. (all other rings have a qlvl (quality level) higher than 49, this makes them impossible to drop.)

For rings, your mlvl sections are as follows:
10-19(Nagel) 20-38(Manald) 39-52(SoJ) 53-65(Raven and Dwarf) 66-67(Bul-Kathos) 68-76(Carrion) 77-83(natures) 84-99(wisp)

each ring’s mlvl range that I listed is the best mlvl range for the best odds of finding that ring. Note that the ring may drop in a higher mlvl range, not a lower one though.

Now, ladder only items may be removed from the list if you are non-ladder. Do not include non-ladder item’s rarity while trying to figure out your odds in non-ladder play. In this case only nature’s peace would be removed but Phase blades, sacred armors and other examples would dramatically alter the results.

Now, everyone knows that only one version of a unique can be dropped in any given game. No more than one of each unique can drop in a game. (assuming Mlvl/ilvl/qlvl restrictions are met.) This is where some of the more advanced players get confused.

Lets say you are in nightmare act 4 and a unique ring drops. This ring ends up being a manald. You think wow, I should run Andariel because my odds just doubled. Well, this is unfortunately not the case. Your odds remain exactly the same as they were but if a unique ring happens to drop from Andariel, you will then know that it is either a nagel or an SoJ. If that original manald happens to get selected a second time, it wil simply drop as a rare ring and you won’t even know it failed because there is no way of checking the durability of a ring, amulet or throwing items.

please refer to http://www.d2data.net/ if you wish to know the rarity of any unique or set item.

Other popular rarity involved items are: Tal's amulet, Auzerewrath, Tyreal's might.

_____________________________________________________

Section 2.0 – The Countess
_____________________________________________________


The countess is the most unique monster of all when items are concerned. This is primarily because of the “rune TC”(TC being Treasure Class). I’ll get into details below.

First, The countess has five checks for her regular TC drop. This TC is called “Countess Item (h)” and can choose from (the highest available TC) “Act 2 (h) Good”. This Treasure Class group can drop items of all types up to a certain maximum. For the widely wanted items, r28*, Armo66* and Wep66*. The no drop percentage for all five checks is approximately 26.6% in a one player game. Keep in mind that I said one player game.

*r28 = LO rune
armo66 contains items such as Ormus’ Robes and Sandstorm Trek. Don’t expect Tal’s Armor :P
Wep66 contains ethreal Edge and ThunderStrokes.

Once all five chances at the above TCs have passed there are three checks from her rune TC (Unless too many attempts succeeded in step one). This TC is called “Countess Rune (H)” and only contains a set number of runes. In this case, it can drop up to and including the IST rune. Odds of attaining an ist are actually best from the Countess, as well as all other runes from this special TC group.

[i]Please Note: Only six items can be dropped by a monster, this makes the countess a very rare thing. Since a possible five items can drop from the first TC group it is possible to only allow one successful drop from the special rune TC. This might sound good at first since the second TC can only drop up to ist but your odds are significantly better in the rune TC and you actually want them to drop as much as possible. It is for this reason that:

Running the Countess is best done in a one player game

The countess can drop the following runes in each difficulty:
Normal
RuneTC: Ral
ItemTC: Ral

Nightmare
RuneTC:io (eye-o)
ItemTC: Ko

Hell
RuneTC:Ist
ItemTC:LO (ell-o)

Listed here are some aprox. chances at attaining specific runes from the countess in hell and Nightmare difficulties:

Hell:

Lo - 0.000312%
ohm - 0.000468%
vex - 0.000546%
gul - 0.000819%
ist - 0.074436%
mal - 0.111654%
um - 0.130038%
pul - 0.195056%
lem - 0.259175%
fal - 0.388763%
ko - 0.514776%
lum - 0.772164%
io - 1.015448%
hel - 1.523172%
dol - 1.976007%
shael - 2.964010%
sol - 3.744013%
amn - 5.616020%
thul - 6.126567%
ort - 9.189850%
ral - 8.752238%
tal - 13.128357%
ith - 10.502686%
eth - 15.754029%
nef - 15.003837%
tir - 22.505755%
eld - 27.006907%
el - 40.510360%

Nightmare:

ko - 0.006651%
lum - 0.009977%
io - 1.028772%
hel - 1.543158%
dol - 2.001934%
shael - 3.002901%
sol - 3.793138%
amn - 5.689708%
thul - 6.206954%
ort - 9.310430%
ral - 8.867077%
tal - 13.300615%
ith - 10.640492%
eth - 15.960738%
nef - 15.200703%
tir - 22.801054%
eld - 27.361265%
el - 41.041898%

Note that these are all chances at players = 1. The odds of runes not included in the Rune TC will slightly increase with more players. An example, the odds of a LO rune with 8ppl is about 0.00056 compared to the above 0.00031, not a big difference but worth mentioning. Also, the more players will dramatically decrease the odds of any rune from the Rune TC.

Main sources:
http://www.flightsofsplendor.com/diabloII/Urlik's_RFG_v2.xls
Several threads posted in the Amazon Basin:
http://www.theamazonbasin.com/d2/forums/

Special Thanks to Lord Urlik for the awesome spreadsheet, Adeyke for some rune TC help and Thrugg for an amazing mini course on TC groups. Ruvanal and RTB should also be mentionned for helping out in the past.