The Diablo 2 Wiki
The Diablo 2 Wiki archive is available for anyone looking for information on Diablo 2. All information here is pre-D2R but contains a lot of useful information that is still relevant. Updated sections for new D2R features can be found on the PureDiablo Diablo 2 section

Ignores Target's Defense

From Diablo 2 Wiki

The Ignores Target Defense property often called ITD is found on various Uniques, Set Items, and Runewords. It can also be added to a weapon by socketing the Jah rune.


The name is somewhat misleading, since it does not mean you will always hit the target. It means that the target's defense is set to zero, so your odds of hitting are greatly increased, but since your character's level is factored against the target's level, the actual to/hit will depend on how that formula plays out.

The greatest to/hit possible in Diablo II is 95%, so there is always at least a 5% chance to not hit, in any situation.