This is my first time as a DM of D&D 4e. I have a character playing a paladin with a blacksmithing background. This player has played a years-long campaign with other friends. He's been looking for materials to craft weapons for his teammates.
He says he can craft anything. For example, a gem from a magical helm was broken thus making it less effective. My player said that he could fix it. Looking through his character sheet, I see nothing that mentions that ability.
Are there limitations on what he can craft? Like it must be his level or lower? Can he craft at all in D&D 4e? Would it be a skill check or it just happens?