Comet is a good observation game, and a good concentration game, for kids.
The 9 of diamonds is the comet. Don't hold it for too long!
Each player picks a card, the one with the highest card shuffles and deals all the cards, face down, one at a time.
It's easier if you arrange your hand by value and suit, alternating red and black suits. Aces are low and kings are high here.
The player on the dealer's left starts and puts his lowest card, of any suit, into the middle face up. He has to say which card he is playing.
He then lays a same suit card, in sequence, on top of that card, face up and any other cards in that suit in sequence, saying which card(s) he's playing.
If he doesn't have the 6 of hearts, his turn is over and play continues to the left.
Each player tries to continue laying cards down in sequence and get rid of her cards.
If she doesn't have the next card in sequence, she has to say "without the six" (or whatever the next in sequence card is) and her turn is over.
If each player takes a turn and no one can add to the sequence, the game comes to a "stop" because it's reached a sequence where the 7 or 8 has been removed from the deck.
The player who layed the last card down starts a new sequence and plays the lowest card in another suit from her hand.
Whoever holds the 9 of diamonds can play the card whenver he wants when he can't continue a sequence, even when the game comes to a "stop".
Laying that card down earns him 2 points.
After laying it down, the holder continues by laying either the ten of diamonds (or the next card in the sequence after the "stop") down.
The winner of the round is the first player to get rid of all his cards.
The winner gets 1 point for each card in the other players' hands, and 2 extra points for every unplayed king.
Remember points earned by playing earlier kings and the comet.
If the 9 of diamonds wasn't played, everyone but the comet holders gets 1 point.
Rounds continue until one or more players pass a preset total - usually 100.
The person with the highest score wins.