A greatly enhanced version of the BASIC computer game Wizard's Castle.
Excerpts from In-Game Instructions
WELCOME TO LEYGREF'S CASTLE
This is a fantasy-adventure game which takes place in Leygref's Castle. The castle is randomly stocked every game, ensuring a different adventure each time you play.
Many cycles ago, in the Kingdom of Zantu, the Grey Elf, Leygrey, forged his Great Orb of Power. Soon after this, he vanished leaving behind his vast subterranean castle filled with esurient monsters, fabulous treasures, crotchety old wizards, a phantom and the incredible Orb of Leygref. From that time hence many a bold youth has ventured into the Grey Elf's castle; as yet, no one has ever emerged victorious.
"The Phantom" is a character moveing and hiding within the game. On every move in which you find yourself in an empty room there is a chance that "The Phantom" will sneak into the room and surprise you and steal something you have... depending on what you have, he may steal Gold Pieces, the 'Charm' you have found, your armor, weapons and flares or even a Treasure that you have found.
To win the game, you must leave the castle alive with Leygref's Orb. The Orb is hidden within a room disguised as a Warp and can only be acquired when you Teleport into that room using the RuneStaff. When you do obtain Leygref's Orb, the RuneStaff disappears.