Green’s Dictionary of Slang

jugging law n.

[? unknown use of SE jug (slang uses are too late) + law n. (1)]

(UK Und.) criminality as it pertains to the corrupt practice of certain games, e.g. dicing or skittles.

[UK]Greene Disputation Betweene a Hee and a Shee Conny-Catcher (1923) 41: The Iugging Law, wherein I will set out the disorders at Nyneholes and Ryfling.