ShiftLeft - card game.
The game uses a standard 52-card deck (Ace, 2, 3, ... , Queen, King).

Solitaire:

Cards are taken out of the deck one after another - backs up. If Card 2 lies directly to the left of Card 1 (of the same value or suit) or 2 cards apart to the left of it, Card 1 is laid on Card 2. Other cards are moved onto the free space to the left. The purpose of the solitaire is to leave as few card decks on the table as possible. The game continues until no move can be made.

Playing with an opponent:

Cards are taken out of the deck one after another - backs up.
First 5 cards are laid then players make moves by turns by solitaire rules. For every covered card a player gets poinst according to the rank of the card. Ace - 1, two - 2, ... , King - 13. If a player cannot move he has to add a card from the deck, at that he gets -1 point for every card.
A game ends as soon as no move can be made.
The purpose of the game is to collect more points than an opponent.

Variant:
At the beginning of the game all cards are taken out of the deck