is a "dungeon crawler" presented in a first person perspective, similar to Eye of the Beholder. Players navigate nondescript, maze-like corridors in their bid to find the princess. The game was released exclusively in Japan, but on April 15, 2006, Deep Dungeon was unofficially translated into English.
The Heretic War is set in the town of Dorl. One day, monsters raided the town, stealing both the treasures and Princess Etna's soul. Despite the attempts of brave warriors to retrieve her soul, none have been successful.
In the dungeon, the player is given a command list. The player can choose to attack if an enemy is in the vicinity, view allocated items, escape from battle, examine the area for items, and talk if there are people nearby. The character's effectiveness in battle is largely determined by numerical values for attacking power (AP), defensive power (AC), and health (HP). These values are determined by the character's experience level (LEVEL), which raises after the character's accumulated experience (EX) reaches a certain point.
is the third installment in the Deep Dungeon series and the first to be released on the Famicom.
is the fourth installment in the Deep Dungeon series.