[TRAILER] The Mandalorian Season 2

[Zardnaar]

it's not just the U.S as pointed out by the link @Morrus posted. 420 (cannabis culture) - Wikipedia
edit: it's more of pop culture than local custom/slang....

Best one they did here was a smoke in. At the local Police station. No arrests were made.

Cops here are very chill unless you start hitting people or throwing bottles.

Or setting couches on fire. Student city.