Block

Block is part of the Evade-Block-Parry mechanics that contribute to a character's defense against an attack roll. Even before the attack roll is made, there is a chance to avoid the attack outright through one of these three means. If a character fails to evade, block, or parry an attack, the various factors involved still contribute to the character's Defensive Strength (DS) when the attack is resolved.

Shield Use is the primary skill involved in block defense. In order to block at all, a character must be holding a shield in the left hand.

Avoidance

The check to determine whether an attack is blocked occurs after the check to determine whether the attack is evaded, but before the check to determine whether it is parried.

The odds for an outright block are determined by comparing the defender's Shield Use skill to the attacker's level. Against a like-level foe, 1x training will yield about a 5% chance to block in stance offensive; 3x training, about 15%. Other factors that affect the chance to block include:

• Stance
• Shield size (Compared to a medium-sized shield, small shields give a -15% chance to block an attack, while large shields give a +15% bonus. Tower shields give a +30% bonus.)
• strength and dexterity
• Positioning: Kneeling reduces one's chance to block by 25%; being prone reduces it by 50%; Stun reduces it by 50% unless you have training in Steady Shield
• Block Specialization, a combat maneuver available to warriors, rogues, and monks, increases your block chance by 5% per rank up to 15%.
• Divine Shield (1609), a paladin group spell
• Spell Block, combat maneuver that allows outright blocking of bolt spells

Defensive Strength

If the attack is not avoided outright, it proceeds to an attack roll where the Shield Use skill contributes to the defender's Defensive Strength. Block DS is only part of the defender's total DS, which is the sum of Evade, Block, Parry, and Generic DS.

Melee Defense

The first step when calculating a character's Block DS bonus is to determine the 'Base Value' portion of the formula. It is necessary to truncate (round down) each factor and to truncate the result after each operation.

Base Value = Shield Ranks + trunc(STR Bonus / 4) + trunc(DEX Bonus / 4)

Example: A character with 55 shield ranks, 23 strength bonus and 29 dexterity bonus would have a base value of 55 + 5 + 7 = 67.

The second step is to enter the base value and the values for the other factors in the appropriate order.

Block DS (Melee) = [(Base Value × Size Modifier × Stance Modifier) / 1.5] + 20 (Shield Bonus) + Enchant Bonus

Note: Perform the operations one at a time, working from left to right, and truncate after each step.

Example: With a 67 base value and a large shield with an enchant bonus of +20, the melee shield DS for this character would be:

Stance OFF

[(67 × 1.15 × 0.50) / 1.5] + 20 + 20 = 65 DS

Stance DEF

[(67 × 1.15 × 1.00) / 1.5] + 20 + 20 = 91 DS

Shield Size Modifiers (Melee)

Replace 'Shield Size Modifier' in the melee formula above with the appropriate value from this table.

Shield Size	Modifier vs Melee
Small	0.85
Medium	1.00
Large	1.15
Tower	1.30

Ranged Defense

Ranged attacks include arrows, hurled weapons and bolts, both from crossbows and magical bolt spells such as Minor Shock (901).

Ranged Shield DS = [(Base Value × Size Modifier + Size Bonus/Penalty) × Stance Modifier] / 1.5 + 20 (Shield Bonus) + Enchant Bonus

Note: Perform the operations one at a time, working from left to right, and truncate after each step.

Example: With a 67 base value and a large shield with an enchant bonus of +20, the ranged shield DS for this character would be:

Stance OFF:

67 × 1.80 + 8 × 0.50 / 1.5 + 20 + 20 = 82 DS

Stance DEF

67 × 1.80 × 1.00 / 1.5 + 20 + 20 = 125 DS

Shield Size Modifiers (Ranged)

Replace 'Shield Size Modifier' in the ranged formula above with the appropriate value from this table.

Shield Size	Modifier (vs Ranged)
Small	1.20
Medium	1.50
Large	1.80
Tower	2.10

Shield Size Bonus/Penalty (Ranged Only)

Replace 'Shield Size Penalty/Bonus' in the ranged formula above with the appropriate value from this table.

Shield Size	Size Bonus/Penalty
Small	-8
Medium	0
Large	+8
Tower	+16

Stance Modifiers

Replace 'Stance Modifier' in the formulas above with the appropriate value from this table. The same values are used for both the melee and ranged formulas.

Stance	Modifier
Offensive	0.50
Advance	0.60
Forward	0.70
Neutral	0.80
Guarded	0.90
Defensive	1.00

Block Chance Formula

Base Block Value

The first step when calculating a character's Block Chance is to determine the 'Base Value' portion of the formula.

Shield Base Value = Shield Ranks + trunc(STR Bonus / 4) + trunc(DEX Bonus / 4)

Example: A character with 303 shield ranks, 30 strength bonus and 25 dexterity bonus would have a base value of (303 + 7 + 6) = 316.

Next, your shield size modifies the Shield Base Value. This will vary between melee and ranged attacks, and uses the same Shield Size Modifier tables above.

Modified Shield Base Value = Shield Base Value * Shield Size Modifier

Example: 316 Shield Base value holding a tower shield vs melee attacks: 316 * 1.3 = 410.

The Third step is to enter the base value and the values for the other factors in the appropriate order.

Base Block Value = [(Modified Shield Base Value * (100 - ((3 * (100 - Stance Block Modifier))/4))/100)

Example: A character in offensive stance with 410 Modified Shield Base Value: (410 * (100 - ((3 * (100 - 0))/4))/100) = 102

Stance	Stance Block Modifier
Offensive	0
Advance	20
Forward	40
Neutral	60
Guarded	80
Defensive	100

Defender Status Modification

Then you apply defender status modifications to the Base Block Value:

• Prone reduces block chance by 50%
• Kneeling reduces block chance by 25%
• Being stunned reduces it by 50% unless you have training in Steady Shield
• You lose 10% of base block for every 25% of spirit missing
• You lose 5% of base block for every 25% HP missing
• Crippled (the UCS effect and PSM Phase 3 effect) are percentage reductions as well but they vary based on the application source
• Sitting is a 25% reduction
• Immobile, sleeping, webbed removes block chance entirely
• Being ambushed is a 50% reduction

Level Modification

Lastly, there is a level modification using the attacker's level. This modification is ((Block * 20) / Attacker Level))

Example

A level 100 Human with str bonus 30 and dex 25 defending a melee attack with a tower shield while kneeling. The attacking creature is level 100

Shield Base Value: (303 + (30/4) + (25/4)) = (303 + 7 + 6) = 316

Melee Shield Type modifies to: Shield Base Value * Shield Size Modifier = 316 * 1.3 = 410

Base Block Value: (Modified Shield Base Value * (100 - ((3 * (100 - Stance Modification))/4))/100) = (410 * (100 - ((3 * (100 - 0))/4))/100) = 102

Then you apply status modifications, which is kneeling in example: Current Block Value = ((102 * Status Modifier) = ((102 * .75) = 76.

Then you apply the level modification of the attacker which is ((Current Block Value * 20) / Attacker Level)) for a final base block of ((76 * 20)/100) = 15%

Shield Specs, CMAN and Spells

Any of the below skills/spells/stances are additive/applied to the calculated block chance.

• Block Mastery
• Tortoise Stance
• Divine Shield

See Also

• Shield
• Evade
• Parry
• Block Mastery
• Combat Guide: Factors, on Play.net