Introduction

People are still asking questions related to upgrading, so I decided to write this relatively simple guide to answer them and hopefully deal with remaining common misconceptions.
The guide is broken into 3 sections each concerning [1] upgrade formulae, [2] upgraded item requirements, and [3] defense calculations.

I have tried to carefully explain every detail. Feel free to ask if something still doesn't make sense to you once you have read the guide. But do make an effort to understand it.

Please report any errors or inconsistencies on topic so that they can be dealt with.


[1] Upgrade Formulae

Q: What can be upgraded ?
A: Only rare and unique items of normal or exceptional quality. Allowed upgrades: normal -> exceptional, exceptional -> elite.

Q: What cannot be upgraded ?
A: Everything else. No, Rune Words are NOT unique items. Don't bother trying.

Q: Where can I find the upgrade formulae ?
A: Right here > http://battle.net/diablo2exp/items/cube.shtml

Notes
- Remember the core limitations stated in the link. Some formulae will not work on non-ladder.
- Gloves, belts, boots, body armor, shields, and helms are upgraded using the SAME formulae, namely the ones for 'armor'.


[2] Requirements of Upgraded Items

Q: What happens when I upgrade an item ?
A: Only the base item is upgraded - the final stats thus depend on the stats of the upgraded base item.
A: Every magical property of the original item remains (including etherealness), as do any gems / runes / jewels you may have inserted.

However, upgrading comes at the cost of increasing the item requirements (Strength / Dexterity / Character Level).

Q: How do I know the Strength and Dexterity requirements of the upgraded item ?
A: They are the same as the upgraded base item requirements. *)

*) The unique item Humongous (Giant Axe) has +20% requirements. Being a magical property, it is carried along if you upgrade the axe.

Q: What if the item is ethereal ?
A: Ethereal items require 10 less Strength and Dexterity than their non-ethereal counterparts.

Q: How do I determine the new level requirement ?
A: This is determined by the lvl req of the upgraded base item, the lvl req of anything inserted (gems / jewels / runes), and on the upgrade(s) performed.

Syrith (quoted @ Baron's Bazaar) put it this way,


Don't get too excited though - we are not done yet.


In other words: the higher of 'upgraded base item lvl req' and 'lvl req of highest modifier on item (including anything inserted)' determines the result.

Alright, let's stop procrastinating and pick a few examples.

(Sharkskin Boots)
Sharkskin Boots require lvl 25 and they upgrade to Scarabshell Boots (exceptional -> elite). Scarabshell Boots have a level requirement of 49. Suppose none of the affixes on the boots
require more than lvl 49. Then,

New lvl req (1st upgrade): 49 + 7 = 56

If the Sharkskin Boots have an affix that forces the level requirement to be, say 53 (> 49), then the Scarabshell Boots would require lvl 58 (53 + 5) to equip.

Twitchthroe (Studded Leather)
Suppose we have inserted a Shael rune - for another 20% fhr. The lvl req of Shael is 29.

The first upgrade (normal -> exceptional) takes Studded Leather to Trellised Armor (base item lvl req: 25). The second upgrade (exceptional -> elite) takes Trellised Armor to Wire Fleece
(base item lvl req: 53).

Now, since max{25,29} = 29 and max{53,29} = 53, we get

New lvl req (1st upgrade): 29 + 5 = 34
New lvl req (2nd upgrade): 53 + 12 = 65

Notes
- The level req of the exceptional version of Twitchthroe is higher than it would have been (30) without the Shael rune. A fact which may be of some concern in low-level-duelling.
- Effectively, we have performed a 2-stage upgrade from normal to elite status (+12 levels), NOT a 1-stage upgrade from exceptional to elite status. That would have been +7 levels.

Bottom line: Work out item requirements before you upgrade.


[3] Calculating Defense of Upgraded Items

Q: How do I calculate the defense of an upgraded X having +Y % ED (Enhanced Defense) and/or +Z Defense ?
A: By following this calculation procedure (applied in the order indicated).

1. Take the minimum and maximum BASE defense values of the upgraded BASE item.
2. (ethereal): Add 50% to the values in 1. Discard any fractions ("round down").
3. (Y % ED): Add Y % to the values in 1 if non-eth (values in 2 if eth). Discard any fractions.
4. (+Z Defense): Add Z (integer defense) to the values in 3 if the item has Y % ED (else 1 or 2).

Notes
- Items having the +Y % ED modifier lose their inherent bonus of +1 to max base defense when upgraded.
- The base defense is rerolled when upgrading. You cannot control this, just as you cannot control the base defense of a dropped Harlequin Crest (Shako).

This is probably both neat and confusing at the same time. We need a few examples to see just how everything works in practice. While the rules are the same for rare and unique items,
we'll confine our attention to uniques, because they have fixed properties (preset range of Y% ED and +Z Defense). As well, they are the ones most commonly questioned in the forums.

Vampire Gaze (Grim Helm): a classic example from Baron's Bazaar and the Battle.net Forums,


Magefist (Light Gauntlets)
2nd upgrade (Crusader Gauntlets)
1. 59-68
2. (skipped)
3 + 4. min_def = [59*1.20] + 10 = 80, max_def = [68*1.30] + 10 = 98

Defense range: 80-98.

Arreat's Face (Slayer Guard) (ethereal)
1st upgrade (Guardian Crown)
1. 117-168
2. min_ethbase = [117*1.50] = 175, max_ethbase = [168*1.50] = 252.
3. min_def = [175*2.50] = 437, max_def = [252*3.00] = 756

Defense range: 437-756.


Commonly upgraded uniques - max defense : exceptional / elite (ethereal).

Note : Adjust the values accordingly if you include a defense enhancing jewel or rune.

Arreat's Face : 504 (756)
Crown of Thieves : 495 (741)
Jalal's Mane : 477
Kira's Guardian : 180 (210)
Vampire Gaze : 314 (470)

Twitchthroe : 178 / 506
Skin of the Vipermagi : 1034
Shaftstop : 1616 (2422)
Guardian Angel : 1590 (2385)

Herald of Zakarum : 579 (867)
Homunculus : 444

Bloodfist : 56 / 88
Magefist : 71 / 98
Chance Guards : 72 / 102
Frostburn : 93 / 115

Goldwrap : 92 / 130

Hotspur : 48 / 80
Goblin Toe : 90 / 123
Infernostride : 170
Waterwalk : 201
Gore Rider : 213

This post was edited by Faelwen on May 31 2008 01:15pm

Very nice guide.

The requirment thing wasn't quite as I remembered it but I was probably wrong about that then.

Sticky imo.

Oh and green > blue ^^

Thanks.


Bah.

To the top.

Only skimmed so far, but this is looking good. Unfortunately, most of the text is hard to read on my selected JSP theme (Pakos). Could you do anything about the yellow/gold/green text? It's just too light.

This color wasn't the best of choice

I cannot edit the first post anymore, so you'll just have to squeeze your eyes together for now. I didn't bother checking every single board display style ("theme").
It may not be the prettiest with Pakos, but except those (few) words in green and yellow everything else is readable. It looks fairly decent with Black/Orange.

This post was edited by Faelwen on Jun 2 2008 06:17am

I'm pretty certain this is wrong, if the previous level requirement was 53, then the upgrade would add 7, making it 60, since the upgrade from exceptional to elite always adds 7, regardless of it originally being a normal item or not.

However, maybe I'm just misinformed =)

Didn't mean to get at you, it was just a little feedback :-).

I know this is addressed in the "What cannot be upgraded" question, but it would hurt to spell out the things that cannot be upgraded. A lot of people ask if crafted, magic, white, even grey/socketed items can be upgraded. I'm not sure why people don't understand a crafted item is not a rare item or even why they ask about magic, white, socketed items in the first place.

I know it's a minor suggestion and overall the guide is excellent at describing and explaining the upgrading process.