The World's of BOB:

    There are 6 Worlds in BOB. Each is 16x8.. 128 blocks. Each
    world has a region name to help you keep track of yourself
    Each world can contain up to 30 sub-worlds. A sub-world
    is exactly that, a world under the world. Each sub-world
    is 5x5.. 25 blocks.  I'll bet that most of the good stuff
    is hiding in sub-worlds.  When you execute a LOOK command
    on a world block and there is a sub-world under that block,
    you will automatically drop into that sub-world. You can
    type L (Leave) to exit the sub-world at any time. Each
    World (region) has 5 cities. Use the LOOK command to enter
    the city. Use the L again to leave the city.
    Hint: Bartenders are full of information. If you ask the
    right questions or have enough Gold.

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