Playing for Second, Third, etc
Prior to the game, players may decide to play until there are two or more winners. In this case, the winner does not reveal the missing gem.
Instead, they replace the missing gem and announce that they were correct. The game continues with the winner answering any interrogations but not otherwise participating in the game.
Additional Missing Gems
When three or four play, the game can be made more challenging by removing two (or three) Gem Cards. The play of the game is the same except that, to win, a player must correctly identify all missing gems.
During their turn, each player may interrogate one or two opponents.
If they interrogate two opponents, they must use a One Element Card to interrogate one opponent and a Two Element Card to interrogate the other, but may use them in any order. After the interrogation, the player draws two Search Cards from the deck.
This variation is played in the usual manner except that cards are never passed. When a Two Element Search Card is used, the opponent simply answers with the number of such cards they hold.