Quesion about the proper use of __slots__

[Zefria]

>>> class Fighter:
...     '''Small one man craft that can only harm other fighters on
their own.'''
...     def __init__(self,statsTuple=(50,5,0,(2,4),1)):
...             self.fuel = statsTuple[0]
...             self.life = statsTuple[1]
...             self.armor = statsTuple[2]
...             self.weapon = statsTuple[3]
...             self.bulk = statsTuple[4]
...             __slots__ =
[self.fuel,self.life,self.armor,self.weapon,self.bulk]
...
>>> ral = Fighter()
>>> ral.rocks = 2
>>> ral.rocks
2
>>> ral.life
5

I was reading the special methods, got to slots
(http://docs.python.org/ref/slots.html) and decided that i should use
this to save memory in the program because it'll have to support very
large numbers of fighers at once. It says that once you define slots
then you can't add any variables not listed in slots, but from that
example section I just did, so am I doing something wrong or did I read
it wrong?