Enemy Critical Hit Rate
From BGWiki
Enemy critical hit rate is a merit category available to all jobs. It can be merited a total of 4 times. Each merit upgrade grants a 1% decrease in the rate of critical hits by enemies against the player. It costs 10 merits to fully upgrade (1>2>3>4).
This is typically merited by general melee. Tanks are well served by this (especially PLD), as are career casters.
