Implied Setting

The White Box World
The LBBs don't map out a setting or world. In fact they refer the player to an Avalon Hill board game for the wilderness map. There are no lists of countries, peoples or gods. The game does imply a setting, however and here's how I think that works. There are three character classes, fighting men, magic users and clerics. That tells the player a lot about how society is structured and what the roads to power are like. Fighting men are warriors, so it's a society that values might. Magic works, both divine and mundane. There is no description of where magic comes from or why it works, but magic users can cast spells that work and some higher level spells are very powerful. Clerics can use divine magic and turn undead creatures. Although there is nothing specific about religion or what divine source powers the cleric's spells, they work and also can be quite powerful, even raising the dead.
Obviously undead exist along with a lot of other creatures not seen on earth today. Player characters can be human (like us except with access to real magic), elves, dwarves or hobbits (races straight out of Tolkien?). Dwarves and hobbits are fighting men (sort of). Elves are magical and alternate between magic user and fighting men (by one interpretation). This tells us that humans, dwarves, elves and hobbits interact and cooperate with each other as a party of adventurers can include members of each "race" (more like species really). I therefore assume the player character races are "friendly". The dungeon denizens are many and I assume they are all somewhat hostile to the player character races. Afterall it there stuff the PCs are expected to take in order to earn experience. The term "monster" is used to describe all the dungeon inhabitants, even humans found in that environment as they are most likely hostile (and up to no good). The LBBs list a chart showing creatures by alignment, those aligned with Law being mostly friendly to the established powers, those aligned with chaos being opposed and those neutrally aligned and of unknown friendliness. PCs don't have to be lawful in alignment, but I get the impression they are encouraged to be lawful. The list of monsters include many from mythology and fantasy literature and the number and variety implies a wild and dangerous setting.
Technology is set somewhat similar to our middle ages with horses and people doing most of the work and weapons and armor resembling what was available during medieval times on earth.  There is no gunpowder, little science or medicine. Most healing either occurs naturally or is magical. There is no mention of birth rank or social class and fighting men regardless of birth can become Lords, build a castle, command followers and hold lands so I presume there is freedom to go as far as your talents take you similar to our own American culture. Of course being the expandable, changeable game that White Box is, the referee is free to make any changes to the implied setting when creating their own unique setting for their game. One's imagination is the only real limit!