A secret lair is dwelling place of
darker evils.
It's secret, as opposed to "
well known", because these evils are doing all sorts of
nasty things they don't want anyone else to know about. Also, if they need to
kidnap a hero's
SO or flee to their lair to nurse their wounds, it's better to have it located somewhere secret and inaccessible, so they can't be easily pursued by
our brave hero.
It's a lair because, for instance, a
secret phone booth or
deviously hidden infinitely large star lacks many of the advantages of a
lair. One can neither nurse their wounds nor
hoard treasure in a phone booth. It is also rather useless for building
doomsday machinery capable of conquering the earth.
Some villains, particularly the "
mad, and
twisted, but
human" types (as opposed to the "
ancient and
dark,
very evil" types) have a
secret castle rather than a secret lair. All a matter of preference, really.
The good guys have a
secret hideout or
secret fortress. Never a lair. It accomplishes the same (albeit good rather than evil) purposes as a lair, but
it is not a lair.
The Old Node Revival Squad!