Dungeons and Dragons, the role-playing game created by Gary Gygax, makes use of the iconic d20 twenty-sided die to create the fantasy world that players explore at length. But the d20 dates back a lot further than you’d expect.
The Metropolitan Museum of Art has the oldest known d20, which dates back to the Ptolemaic Period in Ancient Egypt. It is made from Serpentine and, though it is not on display, is well detailed on the museum’s website.
The die is dated between 304 and 30 BC and is listed both as an ancient die and as a game piece, so it is likely that it was actually used for a game of some sort. The characters carved into the die appear to be of Greek origin. Whether it was ever used for a saving throw is not known.