Where do i go to find out which sets are retired?

http://wizkidsgames.com/wp-content/u...es_2011_05.pdf, specifically paragraph 2.1.1:

thanks :-)

I understand the first half of sharpshooter but the second helf i need help understanding.When they say effects does that mean there powers?

so Avengers and Mutations and Monsters has been retired?

Yes!

The Units Section set list is not reflecting that as of yet.

Everything to the left of Crisis is Modern Age. Everything to the right of Batman: Alpha is Golden Age.