Exploration, Role-play and Combat

The 3 Essential Building Blocks of White Box
What is White Box, or almost any other RPG? This question can be answered in a number of ways, but at it's core I believe the game we play in all its various forms can be summed up as exploration, role-play and combat.
My father once remarked after watching the Lord of the Rings movies, "So that is what you and your friends have been playing all these years." and although Gary Gygax went to considerable pains to frequently point out the differences between LotR and the game he co-created with Dave Arneson, there are some obvious similarities - the struggle between good and evil, travel and exploration above and below ground and combat using magic and medieval technologies, not to mention the presence of dwarves, elves and hobbits/halflings, which along with men, form the cast of characters to be role-played.
A make-believe world to explore, whether a simple dungeon drawn on graph paper or an elaborate setting worked out in minute detail, before play can happen the referee must create certain maps and details concerning the imaginary milieu to be explored.
Some means of resolving conflict, especially conflict that can turn deadly such as the violence that accompanies many adventure stories. White Box focuses on combat between individual heroes and monsters, but also suggests that at least in the later stages of campaign play, violence may need to be played out between groups of soldiers represented by blocks of figures or counters.
The role-playing is what happens when each player assumes control of an individual character rather than a unit of men. How much "in character" acting is done varies considerably from table to table. Some players speak as though the character is a separate pawn, others assume a "voice" for the character and speak in first person as if they are an actor playing a part in a play. The longer a player controls a character, the more complex the character develops and the more attached to the character they are likely to become.
This is the essential elements of the game, exploration, role-play and combat.