In the base game, ten cards are dealt to four players, so players have hands of only two or three cards. As in a trick-taking game, each player plays one card face down in turn order. While doing this, each player forecasts who has the highest card (that is, the culprit). Each card has a color (suit), and you have to show that color when you play the card; this allows opponents to narrow down the number of your card, but some cards have a special effect, so big numbers don’t win automatically. Points are awarded to whoever played the highest card (the culprit) and to whoever correctly forecasted that player winning.
Tricks and the Phantom is not just card luck. It is a strategy inference game that requires you to read each other’s psychology.