Jikuu Yuten: Debias

Jikuu Yuten: Debias (時空勇伝DEBIAS) is a Famicom RPG developed by Now Production and published in Japan by Namco. It was never released outside of Japan, and was never translated into any other language. It came with an accessory, a pair of discs which were meant to be overlaid with one another. At various points in the game, the player was instructed to point the top disc to a particular symbol on the bottom disc and use the results in the game to determine certain outcomes.