Hello. simple question from a person trying to learn the game.. iv seen some deck ideas who use 8 plot cards.. but i see in the rule book it says 7 cards for plots.. am i missing something or are these decks not legal?

if you are playing the LCG (Forum here http://community.fantasyflightgames.com/index.php?/forum/20-a-game-of-thrones-lcg/ ), there are some Agendas that allow you to have more than 7 plots -- 2 from the old CCG, and one in the new LCG)