Created in ancient times, the Moon Tablets serve as a mean for their user to open the door with a moon symbol inside their respective Gaia Gate which leads to certain areas on the continent. In gameplay, these tablets unlock the local continent's Night Stages where Sonic the Werehog is playable. Despite there being seven Gaia Gates spread across the the world there exist only six Moon Tablets, since Mazuri lacks a Night Stage.
Each of the Moon Tablets are designated to a specific Gaia Gate and as such, they cannot susbtitute the Moon Tablet for another Gaia Gate other than their own.
In the game's story, most of the Moon Tablet's lies in the possession of one of the people from the local vilage, which are usually the guardians of the Gaia Temples or someone associated with them. In order to obtain a Moon Tablet for the local Gaia Gate, Sonic must talk to a specific person found on the same continent and they will hand it over to him. In some cases, obtaining the Moon Tablet will reveal the local Gaia Gate on the map.