The fabled Lebowski Challenge: Every time the Dude drinks a White Russian, you drink a White Russian. Every time the Dude does a J, you do a J. That's seven White Russians and four Js.
Another variant is to take a drink every time a character says "dude." TV Tropes takes no responsibility for the vomit stains that will occur.
Or, for a slightly more balanced version - a drink every time you hear "Shut the fuck up, Donny."
And then there's the worst version, only for those who are truly insane: every time The Dude does a substance, you do that substance. This is similar to the first game listed, except it also requires you to roofie yourself two-thirds of the way through the movie.
