Zork

If you were a geek in the 70s and 80s, then you played Zork. Zork was one of the first interactive fiction computer games. There were no pictures, no fancy graphics - just text. The game was programed by four guys from MIT, three who went on to found Infocom in 1979. The original Zork started out:

West of House
You are standing in an open field west of a white house, with a boarded front door. There is a small mailbox here.

You are then able to enter keyboard commands such as: examine mailbox. That command would return: The small mailbox is closed.

It was a matter of trail and error to figure out which commands worked.

I made my own maps to figure out the game and finally finished the first one. I was never patient enough to try and finish the other two in the series. Other Zork games followed the original three and eventually graphic games were introduced. You can still download (for free) the original three games!