We played a 5 player game of citadels. One of the players played his dragon keep (8 points) I had the university though (also 8 points). The only new player at this gam ehad a ton of gold. He told me he was taking the warlord and was going to destroy the Dragon keep. I told him awesome and took the thief. When it came time to do roll call I played the thief and anounced the Warlord. Took all of his gold and then played the Univeristy for the win.

so to all new players TRUST NO ONE

"Never trust another player..." This is true; however, it sounds like the real moral of your story is "Don't tell your opponents what you're going to do next."