Black Bird is a solo dungeon crawler (with auto-map feature): the gameplay consists of exploring maze-like passages in pseudo-3D environment, fighting randomly appearing enemies. The game features card-based combat. Lightning and his opponent are dealt a deck of cards. The goal is to get rid of single cards and to build combinations (three of a kind, straight, etc.), a bit similarly to a poker game. A successfully built combination inflicts damage on the enemy. There are also defense-strengthening and healing cards, which the player can use between the combinations. Beside that, the game has a traditional RPG system with hit points, experience points, leveling up, money management, equipment, etc.
In th early 21st century, Tokyo became the center of advance scientific research. Ground-breaking discoveries were made in the field of computer science, as well as re-discovering the ancient art of magic. A crime organization known as Digital Beast emerged, controlling much of the new technological resources. The organization became so powerful that the authorities were unable to stop its activities. A mercenary named Lightning (or "Light" for short) recently joined a special group named Black Bird. One of his assignments involves investigating strange occurrences in the New Planning company building, which might lead him on the trail of Digital Beast.