This one's a classic, and will get you very pissed. Don't play with anyone who
has a few diseases though. The other downside is you really need to be able to
blow a bit of cash, so it might not be the best student game.

You start off sitting in a circle with a jug (as big a jug as possible; a
number of Wellington pubs, e.g. BackBencher, Molly Malone's have 2.8 liter
pitchers, which are perfect). You drink as much as you like from the jug, then
pass it to the next person. They drink and pass it on. When someone finishes
the pitcher, whoever gave it to them buys the next one. Simple, eh? People will
do anything to get out of buying beer. The game normally starts off with small
sips, but it eventually gets to the level when someone decides they can "go for
it", and attempts to scull the lot. The prick about this is once you start, you
can't really stop, or you'll pass on a pitcher with a few mouthfuls left after
sculling a liter or so yourself...

Playing this with 1-litre jugs is OK after a few rounds; initially, it's fairly
easy to scull a jug, but it quickly starts to get harder.