When the land of Israel was under Seleucid domination, it was originally played to fool the occupying soldiers so they would not detect illegal Torah learning and Mitzvah observance
This is only one of a few theories, and was probably invented after the fact.
Source on that?
עִם סְבִיבוֹן מִשְׂחָקִים בַּחֲנֻוכָּה.
דריידל, איך זיי...