Block rating

Block rating was number typically appearing on items that improved your chance to block an attack. Some abilities, enchantments, items and spells could contribute bonus block rating also (the bonus spell usually has the name "Improved Blocking" or "Increased Block X").

At level 80, players require 16.4 block rating to gain 1% block chance.^{[citation needed]}

Block rating is not to be confused with "block value" which — prior to the Cataclysm expansion — increased the amount blocked (damage mitigation) each time a block occured, rather than affect the chance for a block to occur.

Change in Cataclysm

This section concerns content exclusive to Cataclysm.

Blocked attacks will simply hit for 30% less damage. Block rating will improve your chance to block, though overall block chances will be lower than they were in Wrath of the Lich King.

Pre-Cataclysm

Block chance used to also be increased through defense rating, of which 122.4 rating is needed for 24.88 defense to give 1% block chance, but defense rating was removed with the Cataclysm expansion.