In your adventures in the Wasteland, you may come across seemingly-mysterious" Lockboxes". These rare relics can contain a variety of useful items, including uncommon and rare components, dyes and chemicals, serendipity gear and vehicles and cosmetic items from the Marketplace. In any given box one or more of the above-mentioned items can drop, and it is not uncommon to get 4 or 5 items from Blue Steel and Red Titanium Lockboxes. There are 3 variants of Lockboxes.
Green Copper Lockboxes - Most common Lockbox, contains mostly component caches and lower quality Serendipity items. Can Contain Blue Steel Keys. Unlocked with Green Copper Key.
Blue Steel Lockboxes - Less common Lockbox, typically contains rare and larger component caches, better Serendipity items, and Marketplace cash shop items. Can Contain Red Titanium Keys. Unlocked with Blue Steel Key.
Red Titanium Lockboxes - Rarest Lockbox, contains large amounts of common, uncommon and rare resources, rare dyes and chemicals, the highest quality Serendipity items, and will ALWAYS contain a Marketplace cash item. Unlocked with Red Titanium Key.
Keys can drop off of any Boss or Master creature and are available from Reward Merchants and the Fallen Earth Marketplace. Dropped keys have a rarity following a similar progression to their associated Lockbox type. Easier bosses will have the lowest chance to drop a key. More difficult bosses and masters, such as El Cadejo, have a higher chance. Scavenger Bosses have the highest chance.