The original game on the IOWA system, MirrorWorld ran on a BBC Master 128, with a 32Mb hard disk. Using a custom-developed language known as SLATE, the game was renowned for the difficulty of gaining Wizard status, with only a select few managing to attain the ultimate achievement, many others being content with their status as high-level characters. MirrorWorld was one of the first games to introduce the concept of gradual, puzzle by puzzle resets, rather than resetting the entire game database at once (or area by area). The puzzles were regularly reviewed, so that as more people learned the solution, the value decreased.
MirrorWorld served as an introduction to multi-user games for many people, helped by the non-subscription access to the game, and although the game ran on a normal (i.e. non local call) phone number, it attracted players from all over the country. Fiendishly difficult in places, players had to contend with (and hopefully avoid) sudden death at the hands of the dragon - few players survived to flee from it if they wandered across it unprepared.
Player killing was more-or-less encouraged by the scoring system that rewarded victorious players with a fairly substantial chunk of their defeated foes score. However, combat was not something to get into without thought, as the penalties for defeat or fleeing a combat were severe.