52 are what we would consider a standard deck of cards (with funny suits), and the remaining four cards - Mah Jong (a small bird), Dog, Phoenix, and Dragon - all have special properties.
While the specific rules and packaging of Tichu are new, the play is based on dozens of older card games such as Big Two, President, Zheng Fen, etc. Tichu is a ladder, shedding, trick-taking, partnership card game for exactly four players.
