Fun, game, diversion, or trick. To run one’s rig upon any particular person; to make him a butt. l am up to your rig; I am a match for your tricks.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
See also the definition in Nathan Bailey's 1736 dictionary of canting and thieving slang.
Riff Raff * RiggingNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes