# 100% Block Chance quietly converts a conditional shield stat into an always-on Damage Reduction source

Block Chance and Blocked-Damage-Reduction only exist on Shields/Quarterstaffs, but once Block Chance reaches 100%, every single hit is guaranteed to be blocked - at which point Blocked-Damage-Reduction (base 15%, scalable via shield affixes/Aspects) stops being a conditional roll and functions as a flat, permanent DR source like Armor or Resistance.

Diablo IV patch 3.2.1. Category: defensive. Evidence: Confirmed.

## Detail
Paladin builds explicitly chase this threshold (via Herald of Zakarum, Aegis, and Clash/Punishment per current build guides) precisely because it converts an RNG-dependent defensive stat into a deterministic one, and because it enables Retribution-style builds where every guaranteed Block also triggers an offensive Thorns payoff.

## Why it works
Block Chance behaves as its own additive stat capped at 100%; at exactly 100%, the 'chance' component drops out of the equation entirely and only the Blocked-Damage-Reduction magnitude remains relevant, every single hit.

## Numbers
Base Blocked-Damage-Reduction: 15% of the blocked hit's damage, increased by shield affixes/Aspects.

## How to use it
For Paladin shield builds, treat reaching exactly 100% Block Chance as a priority breakpoint (not just 'more is better') since everything short of 100% still leaves some hits fully unmitigated by this layer.