The player begins in the Barrow from Zork I armed only with the trusty brass lantern and the elvish sword of great antiquity from before. The objective of the game is not initially clear.
Zork II has two notoriously difficult puzzles: the Bank puzzle, in which the player must figure out how to walk through several bank walls in order to figure out how to get out of bank with the loot from the vault without tripping the security alarm; and the Oddly-Angled Room, a diamond-shaped room filed with panes of glass representing baseball bases. The player must figure out how to traverse the diamond in order to open a door that will lead to the game's finale.
This article uses material from the Wikipedia article ZORK II,
https://en.wikipedia.org/wiki/Zork which is released under the
Creative Commons Attribution-Share-Alike License 3.0,