Originally Posted by
Sheras
You can't play the one's on rotation in ranked matches, but by the time you start playing ranked (you have to be lvl 30) you should have a few champs for each role anyways. A lot of people say the non "meta" champs can't win and that is crap, if you know the champion well enough, you can at least go even in every matchup, it's proven by all the one-trick pony players that are ranked really really high. They play one champ, that is off the current-meta so it never gets banned or picked, and play it extremely well.
Examples
DaBox--high diamond one/low challenger Veigar only player--mid lane
Annie Bot--same as above, Annie only--mid/support
Much to Learn--same as above, Fiora player--top lane (and i've seen him jungle)
Azingy--same, Karthus--jungle (he is the only one brave enough to do this most of the time)
BoxBox--diamond one--Riven player--top lane