Of what value is reduction of damage from enemies? Conventional wisdom is that it's a normal difficulty: yes, higher difficulty: no, choice, but there's more than meets the eye. This article addresses the items, damage reduction, and stun elimination aspects. The abbreviation -dfe (minus damage from enemies) is used for items in the osmosis family.

This discussion focuses on 'key monsters' which are common and provide problems which -dfe can address. Looked at are illusion weavers (IW), lava maws and maelstroms (nasty fast attackers), azure drakes and BK's, and the toughest witches, Soul Burners.

Average Damage Table

<strong>Monster Norm   NM  Hell</strong>
IW        20   44   86
Maw       15   34   66
Mael      20   45   86  
Azure     25   52  102
BK        30   64  126
Soul      18   40   78

<em><strong>With -6 dfe:</strong></em>
<strong>Monster Norm   NM  Hell</strong>
IW        14   38   80 
Maw        9   28   60
Mael      14   39   80
Azure     19   46   96
BK        24   58  120
Soul      12   34   72

Some monsters have a wide range of dmg, like 1-35 for soulies, which make the avg dmg calculation a bit complicated for large -dfe.

Let's define EHP as effective hit points, an equivalent number of hit points to compare to 100 hp with no -dfe.

<em><strong>EHP for -6 dfe per 100hp</strong></em>
<strong>Monster Norm   NM  Hell</strong>
IW       142  115  107
Maw      166  121  110
Mael     142  115  107
Azure    131  113  106
BK       125  110  105
Soul     152  117  108

Significant in low difficulties, but nothing major. Things get more interesting when you wear multiple -dfe items, as shown in this table.

<strong>dfe         -1        -2         -3         -6        -15        -30      +15</strong>
<em>-- Normal Diff --</em>
IW  105  111  117  142  409  2000  57
Maw  107  115  125  166  1100  1500  50
Azure  104  108  113  131  250  2343  62
BK  103  107  111  125  200  2200  66
Soul  106  113  120  152  707  1615  54
<em>-- NM --</em>
IW  102  104  107  115  151  314  74
Maw  103  106  109  121  178  939  69
Azure  101  104  106  113  140  236  77
BK  101  103  104  110  130  188  81  
Soul  102  105  108  117  161  415  72
<em>-- Hell --</em>
IW  101  102  103  107  121  153  85
Maw  101  103  104  110  129  183  81
Azure  100  102  103  106  117  141  87
BK  100  101  102  105  113  131  89
Soul  101  102  104  108  123  163  83

(These assume you have resistance to magic for the soulie numbers.)

So how many HP is -dfe worth?

More extensive calculations along these lines were used for several typical cases, and some generalizations. Warrior with 500hp, DSC, HD+Gotter+DSC, and HD+Gotter+Carapace, Rogue with 250-300 hp wondering whether to use Stormshield or Holy Defender, a Rogue SNOB, and Sorcerer with 750 mana using Scavenger's Carapace.

<strong>
Class        DFE    Norm       NM       Hell</strong>
Warrior   -6 dfe    2Whale     Whale     Tiger
Warrior  -12 dfe    5Whales    2Whales   Mammoth
Warrior  -21 dfe    Immunity   4Whales   2Mammoth
Rogue      SS/HD    Mammoth    Tiger     Eagle
Rogue    -30 dfe    Immunity   5Whales   2Whales
Sorc     ScavCar    Immunity   4DROWs    3Dragons
 
<em>... So each -6dfe is about worth:</em>
Warrior            2Whales     Whale      Tiger
Rogue(SSv