Dilemma or Dubito is played with two or three decks of standard playing cards. Each player is dealt a hand of eight and the remainder form a draw pile.
On a turn, a player plays one card to their layout and then draws a replacement. A player's layout consists of four lines of cards:
1. Cards that increase in value
2. Cards in the same suit
3. Cards in the same suit that increase in value
4. Cards of the same rank
These lines are fixed at the start of the game (i.e. a player cannot play to a line and decide later which one it is.)
The game ends when no one can play any longer. Players score one point for each card in line 1, two for each in line 2, etc.
The book versions of the game (German and second English) suggest playing with two decks even with more players and also give some variants:
In Subito a player may play multiple cards on their turn, replenishing only after all cards are played. (With two players use just one deck.)
In Judico players do not have hands; instead on a turn a player draws a card and then may play it or discard it. Discarded cards are out of the game. The rules for the lines are relaxed in this version.