FAQ: http://wizards.custhelp.com/cgi-bin/wizards.cfg/php/enduser/std_adp.php?p_faqid=1396
From the feats chapter:
Am I missing something?
Problem: The answer is missing the point.Can a Fighter with a 12 Constitution still use scale armor?
The Armor Proficiency (Scale) feat requires a 13 Constitution, but all fighters gain proficiency with scale armor for free (regardless of the prerequisites).
From the feats chapter:
Yes, the Con 12 fighter is proficient with scale armor. But can he use it? As far as I can tell the PHB says "no".PHB 193 said:If you ever lose a prerequisite for a feat (for example, if you use the retraining system to replace training in a prerequisite skill with training in a different skill), you can’t use that feat thereafter.
Am I missing something?