New, and I have a question about the format change over

[Keyblader]

I'm not 100% sure where to post this, but I thought this sounded appropriate. A few weeks ago i got really excited to start collecting again, I used to collect when I was a kid but just for the cool pictures and I loved pokemon. I'm 20 now and still play the handheld games, but recently decided that I wanted to play TCG after learning how finally on the TCG online beta.

My question is how exactly does a format change work? And how long do cards usually stay playable for. If I'm not mistaken starting September 1st, all the HGSS cards will no longer be legal in competitive play. What exactly are the limits on what can and can't be played. Is that all of the cards? Or just a select few?

Any help on this would be greatly appreciated, I think i have come at a good time to start getting competitive since Dragons EX comes out on Tuesday and I'll get a fresh start there, I have a lot to learn but I am very excited to.

[waynegg]

Anything from before Black and White, unless it has been reprinted in a BW-on set ( such as Pokemon Communication and Double Colorless Energy) aren't legal for organized play. A set of cards stays "in rotation" for about 2-3 years.

[SMP88]

Only cards from the following sets will be legal starting right now:

Black and White
Emerging Powers
Noble Victories
Next Destinies
Dark Explorers
Dragons Exalted
BW Promos
BW Trainer Kits
McDonalds Promos '11 & '12