That second element becomes active when certain cards cause the field to be "flipped".

Some examples include finding a certain card in a deck of cards.

Only certain cards, known as counters, have point value.

After all, they still had certain cards to play.

I merely placed certain cards on the table and asked you to match them.

"Seven-O" means passing your hand to the next player when a certain card is played.

Should a player indicate that he holds a certain card in his hand.

Object of the game is to get the most points based on winning certain cards.

Crews also had various traits that allowed them to use certain cards.

A joker can be played if a player doesn't have a certain card.