Thanks to Marsyas, Professional Archeologist, I got this fascinating article on a Ptolemaic bronze d20 found in Alexandria:
Paul Perdrizet, "Le jeu alexandrin de l'icosaèdre", in Bulletin de l'Institut Français d'Archéologie Orientale n°30 (1931), p. 1-16.
Each side of the icosahedron has a numerical value from 1 to 48 but also a word, which is supposed to be the name of that roll. It seemed to be a simple game of chance, like knucklebones (astragaloi).
1 Value 1. Kaunos (Outcome of drawing lots).
2 Value 3. ? (maybe Anthos = Flower ?).
3 Value 6. Prosabbaton (Eve of the Shabbat, Sixth Day)
4 Value 8. Polups (The Polyp or The Octopus)
5 Value 9. Mousai (The Nine Muses).
6 Value 12. Horai (The Twelve Hours).
7 Value 14. Tripsorkhis (Ball-Kicker)
8 Value 16. Numphè (The Young Bride)
9 Value 17. ho Kalos (The Beautiful Man)
10 Value 18. ? (unreadable)
11 Value 22. Semata ("Tombs")
12 Value 23. Aphrodisios (The Venus Throw)
13 Value 24. Berenike (deified Berenice II of Egypt)
14 Value 25. Ephebos (The Ephebe)
15 Value 26. ? (erased)
16 Value 27. Puthia (The Pythian Games)
17 Value 28. Bômoi (The Two Altars. Maybe Isis & Serapis, or The Dioscuri?)
18 Value 29. Athlophoros ("Bearer of Victory Prize", Priest of the deified Berenice II)
19 Value 35. Gumnasiarkhos (the Gymnasiarch)
20 Value 48. Sōtḗr ((Ptolemy) the Savior)
As you can see, the Natural Twenty was already called a "Saving Throw" (named after the founder of the Lagid dynasty). The numerical value of the Macedonian Pharaoh (48) was the double of the Queen's Berenice Throw (24). The Hellenized name of the Prosabbaton (Friday) came from the Jewish community in Alexandria.
The Tripsorkhis seems to be an obscene reference to cheating (roughly, Crusher of Genitalia).
See also the British Museum collection of polyhedral dice.