Frequently Asked Questions
Do I have max block when my shield reads "Chance to Block: 75 %" ?
* You cannot tell from the shield alone.
Chance to Block on the shield (including the Paladin Holy Shield bonus) is capped at 75 % for display only, while it may be higher.
For the true Chance to Block, which is in fact capped at 75 %, hover your cursor over the field labelled "Defense" in the character screen.
What is the difference between Faster Block Rate and Increased Chance of Blocking ?
* Faster Block Rate (FBR) improves your blocking speed, provided you reach certain FBR breakpoints (transition values).
Increased Chance of Blocking (ICB) improves your odds of successfully shield-blocking an attack.
FBR has nothing to do with CtB. ICB has nothing to do with blocking speed.
How about FBR and ICB bonuses ?
* FBR applies to claw-blocking (Assassin Weapon Block) and shield-blocking. ICB applies to shield-blocking only.
Blocking penalties while running/walking ?
* Shield
When running, CtB is divided by 3 after the 75 % cap and Defense is ignored in the hit check. The same applies to the Paladin Charge skill.
When walking, there is no penalty.
* Weapon Block
When running/walking, CtB = 0. When running, Defense is ignored in the hit check.
What do shields block ?
* Most physically delivered attacks, including kicks, missiles (arrows, bolts), and spells of physical nature (Barbarian War Cry, Druid Tornado).
Tornado is blockable after the initial turn it makes on the ground.
Smite cannot be shield-blocked.
What do claws block ?
* All attacks and spells except so-called "ground spells" (AoE), e.g. Mind Blast, Firestorm, and Meteor (burning ground fire).
Blocking Formula
The following applies only to shield-blocking. As such, the true CtB ( T ) is calculated from a total ( B ) of your blocking bonuses, your Dexterity ( D ), and Character Level ( C ),
Code
T = [B * (D - 15) / (2 * C)] , true Chance to Block (%)
The game uses integers, so division truncates [ ], i.e. the final value is rounded down (and capped at 75).
Ref: Diablo II Strategy Compendium, Chance to Block
Blocking Bonus ( B )
A total of the value inherent to a particular class (Class Bonus), the shield-specific value (block in Armor.txt), and any other ICB bonuses from items (including on the shield).
Class Bonus
* Paladin: +30 (%)
* Amazon, Assassin, Barbarian: +25 (%)
* Druid, Necromancer, Sorceress: +20 (%)
Code
(Base Defense) (qlvl) (max Sockets)
name block minac maxac durability reqstr levelreq level speed gemsockets
Buckler 0 4 6 12 12 0 1 0 1
Small Shield 5 8 10 16 22 0 5 0 2
Large Shield 12 12 14 24 34 0 11 5 3
Spiked Shield 10 15 25 40 30 0 11 0 2
Kite Shield 8 16 18 30 47 0 15 0 3
Bone Shield 20 10 30 40 25 0 19 0 2
Tower Shield 24 22 25 60 75 0 22 10 3
Gothic Shield 16 30 35 40 60 0 30 5 3
Defender 10 41 49 68 38 22 34 0 1
Round Shield 12 47 55 64 53 25 37 0 2
Scutum 14 53 61 62 71 25 42 5 3
Barbed Shield 17 58 78 55 65 25 42 0 2
Dragon Shield 18 59 67 76 91 25 45 0 3
Grim Shield 20 50 150 70 58 25 48 0 2
Pavise 24 68 78 72 133 25 50 10 3
Ancient Shield 16 80 93 80 110 25 56 5 3
Heater 22 95 110 88 77 43 58 0 2
Luna 20 108 123 84 100 45 61 0 2
Hyperion 24 119 135 82 127 48 64 5 3
Blade Barrier 20 147 163 83 118 51 68 0 3
Monarch 22 133 148 86 156 54 72 0 4
Troll Nest 20 158 173 74 106 57 76 0 3
Aegis 24 145 161 92 219 59 79 10 4
Ward 24 153 170 100 185 63 84 5 4
Targe 10 8 12 20 16 3 4 0 4
Rondache 15 10 18 30 26 6 8 0 4
Heraldic Shield 20 16 26 40 40 12 16 0 4
Aerin Shield 22 26 36 50 50 15 20 0 4
Crown Shield 25 30 40 60 65 18 24 0 4
Akaran Targe 10 101 125 20 44 26 35 0 4
Akaran Rondache 15 113 137 30 59 30 40 0 4
Protector Shield 20 129 153 40 69 34 46 0 4
Gilded Shield 22 144 168 50 89 38 51 0 4
Royal Shield 25 156 181 60 114 41 55 0 4
Sacred Targe 30 126 158 45 86 47 63 0 4
Sacred Rondache 28 138 164 68 109 52 70 0 4
Kurast Shield 25 154 172 55 124 55 74 0 4
Zakarum Shield 22 169 193 65 142 61 82 0 4
Vortex Shield 19 182 225 90 148 66 85 0 4
Preserved Head 3 2 5 20 12 3 4 0 2
Zombie Head 5 4 8 20 14 6 8 0 2
Unraveller Head 8 6 10 20 18 12 16 0 2
Gargoyle Head 10 10 16 20 20 15 20 0 2
Demon Head 12 15 20 20 25 18 24 0 2
Mummified Trophy 3 38 48 20 38 24 33 0 2
Fetish Trophy 5 41 52 20 41 29 39 0 2
Sexton Trophy 8 44 55 20 47 33 45 0 2
Cantor Trophy 10 50 64 20 50 36 49 0 2
Hierophant Trophy 12 58 70 20 58 40 54 0 2
Minion Skull 3 95 139 20 77 44 59 0 2
Hellspawn Skull 5 96 141 20 82 50 67 0 2
Overseer Skull 8 98 142 20 91 49 66 0 2
Succubus Skull 10 100 146 20 95 60 81 0 2
Bloodlord Skull 12 103 148 20 106 65 85 0 2
A Monarch (block=22), for instance, will display Chance to Block: 52 % (30 + 22) for Paladins, 47 % for Amazons, Assassins, and Barbarians, and 42 % for Druids, Necromancers, and Sorceresses.
ICB Bonus
(see the final section for a complete list of items with ICB).
* Safety Amulet: +1-10 % ICB:
http://classic.battle.net/diablo2exp/items/crafted/safety.shtml* Guardian Angel Templar Coat: +20 % ICB, Twitchthroe Studded Leather: +25 % ICB
* Holy Shield: (see the next section)
* Eld Rune: +7 % ICB, shld
Sorceress, Spirit Monarch, D = 75, C = 80
Assuming no items provide ICB, we have B = 42 (Monarch, sor),
T = [42 * (75 - 15) / (2 * 80)] = 15 (%)
Spirit is not a great shield for max block. Sorceresses aiming for max block tend to use Moser's Blessed Circle Round Shield, Whitstan's Guard Round Shield, or Stormshield Monarch.
Paladin, GA, HoZ, level 20 HS, D = 114, C = 90
Herald of Zakarum Gilded Shield {upgrade: Zakarum Shield} has CtB: 82 % (30 + 22 + 30), Guardian Angel offers +20 % ICB, and a level 20 Holy Shield amounts to +35 % ICB. Thus, B = 82 + 20 + 35 = 137 and
T = [137 * (114 - 15) / (2 * 90)] = 75 (%)
Even if we were to replace the chest piece, we would still only need 131 Dexterity to reach max block. Notice how close this is to the required Dexterity (136) of a Phase Blade. Smiters using HoZ and a PB basically do not have to worry about max block and thus can save more points for Vitality. HoZ, level 27+ Holy Shield, and 140 Dexterity will ensure max block all the way to level 99.
Holy Shield
This skill has three crucial features making it invaluable,
1. HS adds directly to the blocking variable, B, implying less Dexterity required for max block.
2. HS significantly enhances Defense (not just the shield here, but the total).
3. HS improves the block rate (see Speeding up Blocking).
The table below lists Holy Shield breakpoints; minimum levels of HS needed for an increase in the ICB bonus to B,
Code
Holy Shield, Increased Chance of Blocking (+X %)
14 18 20 23 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
slvl of HS 1 2 3 4 5 6 7 8 9 10 11 13 14 16 20 23 27 36 45 60
Smite +{Y,Z} | {1,4} + 2*slvl | | {17,20} + 3*(slvl - 8) | {41,44} + 4*(slvl - 16)
+% ED 10 + 15*slvl
Duration (s) 5 + 25*slvl
Formulae for bonus to Smite Damage (note that these are different for skill levels 1-8, 9-16, 17+), +% Enhanced Defense, and Duration of Holy Shield are given in the table.
Internally, Holy Shield is known as one of the dmXY skills (diminishing returns), with parameters 10 and 40 assigned in Skills.txt, which means you can verify the above values of X using the following formula (graphed below),
* X = [ (40 - 10) * [110 * slvl / (slvl + 6)] / 100 ] + 10
On a sidenote, the +% EIAS from Fanaticism follows the exact same formula, using the same parameters.
Max Block
In order to optimise our chance to block, we need to know the minimum Dexterity ( D_min ) required for max block ( T = 75 ) at a given level ( C ). There are at least three ways to do this,
1. As mentioned earlier, check the "Defense" field. Add 1 Dexterity at a time until the chance to block reaches 75 %.
2. Use a block calculator. Google: PPR Blocking Calculator (Peter Paul Ruben's Blocking Calculator).
3. Invert the blocking formula, expressing D_min in terms of B and C to ensure T = 75. Since T is a truncated value, we get the following 'inverse' formula,
Code
D_min = {150 * C / B} + 15 , minimum Dexterity for max block
where { } indicates rounding up.
For reasons given above, different classes using the same shield may need different amounts of Dexterity to maintain max block. In particular, Paladins with HS will have a 'large' B and hence a 'small' D_min compared to other classes at equal levels. Check the graphs below for an example.
The Pal (HS20) graph is deliberately not extended to character levels 29-42; Holy Shield is a tier 5 skill (levelreq 24) which means you cannot have a level 20 HS before clvl 43 (unless you have some skill adders).
Deviations from straight lines are due to rounding in the formula for D_min