Being drunk can do a lot of things to you, few of them
good.  Your mental statistics suffer when drunk and your
dexterity and agility can also be impacted.  However, your
strength and constitution can increase when drunk.  Get
drunk enough and you'll pass out.  Your ability to get drunk
is directly related to your ability to be poisoned -- if
you're immune to one, you're immune to the other.
Similarly, spells that remove poison remove drunkenness as
well.  Drunk characters will find themselves doing naughty
things they would never do when sober (we hope).  Drink at
your own risk.  Most guilds agree you should never slay
drunk, though Jomsvikings seem to enjoy it.