Question about Ignore Target's Defense.

[ZackulDiablo]

How does it really work? I know it has no effect in PvP, but what about PvM? I heard that you will always hit a monster when you have ITD even when your AR is crap. How does it work on bosses?

[Eilo Rytyj]

It pretty much only works on normal monsters. It doesn't work on Champions (or similar types), Uniques, Super Uniques or act bosses.

For normal monsters, it's like the monster's defense stat is 0, giving you a 95% chance to hit.

[krischan]

Not quite. The to hit formula looks like this:

Chance to Hit % = 100 x AR / (AR + DR) x 2 x Alvl / (Alvl + Dlvl)

AR= attacker's attack rating, DR = defender's defense rating, Alvl = attacker's level, Dlvl = defender's level.

ITD sets the defender's DR to 0, so the underlined part becomes 1, turning the formula into into this:

Chance to Hit % = 100 x 2 x Alvl / (Alvl + Dlvl)

That means if your level is at least the enemy's level, the formula provides a 100% chance. However, the chance has an upper cap of 95%. The highest level of regular monsters is 85 which means that ITD works at its optimum from L77 on.

Bosses and players are immune to ITD. For that purpose, -x% target defense is better, as it works at half strength versus them.

ITD and -x% target defense have no effect on blocking and the dodge/avoid/evade skills from amazons.

[SSoG]

Bosses and players are immune to ITD. For that purpose, -x% target defense is better, as it works at half strength versus them.

Minor nit. Gear-based "-x% target defense" (such as from Eths socketed in your weapon) operates at half-effectiveness against bosses (so -100% defense becomes -50% defenses against Champions and better). Skill-based "-x% target defense" from the skills Battle Cry and Conviction work at full effectiveness against all monsters. A slvl 26 Battle Cry will provide -100% enemy defense, which is the exact same thing as ITD that will work for everyone in your party against every enemy in the game.

[thegiantturtle]

A slvl 26 Battle Cry will provide -100% enemy defense, which is the exact same thing as ITD that will work for everyone in your party against every enemy in the game.

...unless the enemy is a barb with iron skin, a paladin with holy shield, or any character under shout. In these cases, the -100% defense Sums with the +% bonus from the skill.

Example:

Druid has 2000 defense. Druid gets shouted for +150% defense. The druid now has 2000 * ( 1+ 1.5) = 5000 defense. If the druid gets hit with a level 26 battle cry, he would have 2000 * ( 1 + 1.5 - 1) = 3000 defense.


I can't remember if there are any boss properties that add skill based +% defense to enemies, so I don't know if this ever would be a problem in PvM.

[anilrobo]

Resurrecting this really old thread with a question:

I have a fishymancer, with an Eth rune in the weapon (-25% target defense). I'm standing in Baal's throne room, but not really attacking Baal. My skeletons and mages are busy hitting Baal. Do I still get the -25% target defense just by standing there with the weapon in my hand, or do I have to really hit Baal for this mod to become active?

[udgard]

-25% target defense works on the chance to hit calculation of the player who is using it. That means if you're not attacking, no chance to hit calculation is made, thus the mod doesn't do anything. And no, it doesn't benefit your minions even if you hit Baal with it.

[anilrobo]

But Nightfish's guide recommends that you use a six socketed sword with Eth runes in it, and hit the boss few times to reduce their defense to zero. Are you sure?

[krischan]

No, his necromancer uses such a weapon to have an easier time at dealing crushing blows (deals a certain percentage of the enemy's life, no matter how much it is, making it very useful versus tugh enemies). An Eth runes reduces target defense by 25% and 6 reduce it by 150%. That works only at half strength on bosses, so when his necro attacks one, it will be 75% less for all attacks with that weapon made be the necro, but not for anybody else.

I'm 100% sure about that.

[lumpor]

Either he was wrong or he meant to like also equip guillames and attack the boss yourself to apply crushing blow.