Warhammer: Vermintide 2

Exotic items are the highest attainable item to achieve through upgrading. Rarity scaling goes from common:gray < uncommon:green < rare:blue < exotic:gold/red. At around level 12 you will start getting chests that may contain an exotic and almost certainly will have rare items and yes the basic chest, these items can simply be equipped or upgraded. To be able to upgrade you must use salvage in the forge to obtain upgrade materials based on the item but I've found from rare to exotic takes 40/50 copper which is the most common salvaged item. I recommend whenever opening a chest equipping the most powerful items in your inventory and salvaging everything else every time.

Important Note: This achievement doesn't seem to require every slot to be filled at once so this can be done over time and will come naturally on the way to level 30.

This isn't a complete walkthrough but should give an idea on how to get these items so if you have suggestions or questions help me make this guide better by leaving a comment.