I happend to see a list of all the restricted cards. However, I still don't get it: how restricted exactly? I mean what rules are applied to using restricted cards? I guess I can still include restricted cards into my deck because at least they're not banned, but if this case, then they're as normal as those non-restricted cards?? So confused.

You can have ONE of the cards in your deck (up to 3x of that card). Having 2 or 3 or any combination of the listed cards in your deck is not allowed.

You get one off the list.

The list is published in the FAQ, which is where you'll find the explanation you're looking for. But yeah, what AceMan said.

Thank both of you.

Being on the Restricted list is like "House X only." It is a deck-building restriction. It means absolutely nothing for how the cards act once the game starts.