Magic Item Compatibility

Magic Items made by blacksmiths work as normal, However there is a special rule for items found in Dungeons. These items have existed for eons, and have all gained a very limited form of sentience. This expresses itself in a compatibility system.
Items from Dungeons choose whether or not those who attempt to touch them are allowed to use them. This is true for both attuned and non-attuned items. The general rule is that items prefer those who can use them effectively. So a Sword will often refuse to be used by a monk or a spellcaster, unless that spellcaster has proficiency with the weapon and a predisposition to actually use it.