A drunken form of foosball, with many rules, slaps, and even debauchery depending on your level of intoxication and character or lack-there-of.
It's no beer pong, Thank God.
Requirements: 4 peoples, A shit load of booze, a regulation foosball table.
Tom: Let's get fucking plastered tonight.
Dick: I'd rather live up to my name and just play foosball.
Harry: Now, with this definition written, it's possible to do both with boosball! *thumbs up*