Realms of Darkness

Realms of Darkness was developed by American programmers Gary Scott Smith and Alex Duong Nghiem. It was released by Strategic Simulations in 1987 in North America for the Apple II and the Commodore 64. Two years later, in 1989, it was localized to Japan with the title Rogue Alliance (ローグアライアンス is a reading help on the Japanese box cover) for several systems.

The game had a heavy copy-protection system that made it difficult to run even on the original hardware.

More than 30 years after its original release, the only way Realms of Darkness can be played today is through emulation.
 * When emulating the Apple II version, the game crashes whenever a combat starts.
 * The emulation of the Commodore 64 version works better, but it crashes whenever the player attempts to resume a previously started game. Still, the problem can be bypassed in a specific old version.

Story

 * From the game text transcript

The guard says: "Greetings, travelers. Would you be interested in an adventure?"

"The royal sword, Zabin, was used by our first king, but was lost during an ancient battle. Recently, we found a scroll which leads us to believe that it is currently residing in the ruins to the northeast of the city. If you brave adventurers can return Zabin to us, you will be well rewarded."

Gameplay
Realms of Darkness is a hybrid between a role-playing game and a text adventure game. Both genres are text-rich and allow free exploration. From the role-playing side, the player controls a party of adventurers whose attributes improve permanently during the adventure, mostly through combat. From the adventure side, it includes a text parser to interact deeply with the fictional game world and its inhabitants.