The Dungeon Robber game is about what happens before your first game of Dungeons and Dragons, before your character has fighter or wizard skills and can afford decent equipment. But if you’re successful enough to retire as a merchant, a thieves guild moves to town. If you retire as a knight, you’ll be able to start your next game as a fighter. Eventually, when you’ve unlocked the four original D&D classes and starting equipment, you’re actually playing D&D.
Source: [ The Developer Website].
Dungeon Robber is a rogue-like game using the Dungeon Masters Guide (AD&D 1e), Appendix A: Random Dungeon Generation rules by Gary Gygax. You delve into a dungeon as a class-less level 0 character and as you progress you can unlock four classes, cleric, fighter, thief and wizard.
RPGGeek entry Dungeon Robber