OBJECT:
The object of the game is to score the most points either in a single round or over a series of rounds. Points are scored by playing out cards representing the CNO cycle.
SETUP:
Both players shuffle their decks. Each player counts out 15 cards face down. This becomes their HAND. The remaining cards become the STOCK. Four cards from the stock are laid out face up in front of each player. These four spots are the PLAY ROW. The top card of the stock is always visible as is the top card of the hand.
PLAY: Players play cards from their stock, play row, or hand onto reaction piles in the center of the table. All players may play their cards onto any reaction pile, unless the top card of the pile is Neon-20 (20Ne), see below.
Since the lowest element in the CNO cycle is Carbon-12 (12C), 12C is the only card that can be used to begin a reaction pile.
The maximum number of reaction piles is 2x the number of players.
Players play cards onto the reaction piles so as to follow the chain of reactions in the CNO cycle. Each card has one or more isotopes listed in the upper left hand corner as an aid as to which cards it can be played on.
Players may play cards directly from their play row. That slot on the row is replaced by the top card of the stock and the top card of the stock is flipped over.
Players may play cards from their hand by cycling through the cards in their hand one by one. Once a player has cycled through all the cards in their hand, they can begin again at the beginning of their hand. This can repeat any number of times.
A player may, at any time, remove a 20Ne card from the play row, the top of the stock, or their hand. If they do, then that card then neither counts for or against the player (see SCORING, below).
Once a 20Ne is placed on top of a reaction pile no new cards may be played on that pile. This pile still counts as a reaction pile with respect to the maximum number of allowed piles (2x number of players).
Whenever a player exhausts his or her stock or empties his or her hand, that player may declare "Done". At this point the round ends and points are scored. A player does not HAVE to declare that they are done as soon as they are finished. They may continue to play cards.
SCORING: For each card played onto a reaction pile, the player who played it gets 2 points. For each card remaining in their hand, play row, or stock, each player loses 1 point. For each card in a reaction pile topped by 20Ne, the player who played the 20Ne card gets 1 point.
Whoever has the most points is the winner.
SPECIAL RULE:
In the event that no player can make a legal play from the play row or hand AND all players still have cards in their stock and hands, the top card of the stock and the cards in the play row are placed on the bottom of the stock and a new play row is laid out and the new top card of the stock is turned face up. This process repeats as necessary. If no player can make a legal play from the play row or hand, but one or more players do not have cards in either their stock or hand, the game ends.
