Conflict with Sierra over royalties for the IBM port of this game led the series creator Richard Garriott to start his own company, Origin Systems.

[2] From the game's story, the player learns that the lover of the dark wizard Mondain, the enchantress Minax, is threatening Earth through disturbances in the space-time continuum.

The young Minax survived her mentor's and lover's death at the hands of the Stranger (in Ultima I: The First Age of Darkness) and went into hiding.

Minax's castle, named Shadow Guard, can only be reached through time doors (similar to moongates in the later games); even then an enchanted ring is required to pass unhurt through the force fields inside.

Sierra On-Line agreed and provided Garriott, who had left the university, with technical assistance as he developed his first major assembly language project.

[citation needed] Despite reservations of Richard Garriott and Chuck Bueche, the original Apple II version of the game was copy-protected using Sierra's new Spiradisc system.

This "enhanced" version was only available as part of the Ultima Trilogy I-II-III box set released that year and discontinued only months later.

[11] The game is known to run without errors and at an acceptable speed in a DOSBox environment, provided the missing map files are present.

The Atari ST port was one of the earliest commercially released games for the system, coming out shortly after the computer's June 1985 launch.

Softline in 1983 stated that Ultima II "continues the interplanetary saga with a creative programming flair far beyond the scope of most fantasy or adventure games".

The magazine concluded that "Lord British has another, greater hit on his hands ... the ultimate in real-time D&D type fantasy games for the micro".

[14] Computer Gaming World in 1983 gave Ultima II a positive review, noting many improvements over its predecessor, particularly in the amount of detail.

The magazine described it as "an animated graphic adventure game" and stated that Ultima II "is more sophisticated and has a quicker pace" than its predecessor, with a "fascinating" world.

[18] PC Magazine gave Ultima II 15.5 points out of 18, also praising the game's "great big wonderful world".