SwordThrust was an improved version of Eamon (a public domain RPG also produced by Donald Brown). Unlike most games of its era, it was modular. This game, the so-called Master Disk, contained the main program and one adventure. Then subsequent adventures were released, which required this Master Disk to play. This is a similar model to the Epyx DunjonQuest series. Sometime around 1985 CE entered into a contract with Softsmith to distribute the SwordThrust series in its Kiosks. To accomplish this, Softsmith developed its own package AND used its own protection scheme. This meant that CE copies and the Softsmith copies were not interchangeable! The game itself is quite advanced for its time, with a sophisticated, highly mathematical combat system and a text adventure-like interface. It is also one of the few commercial all-text RPGs.