The challenge of Slide is to rid yourself of cards to leave as few points as possible.
To set up, deal sixteen cards to each player, who arranges them in a face-down 4x4 grid. Cards range from 1 to 10, with ten copies of each number.
To start, each player reveals a card of their choice from the grid. Starting with whoever revealed the lowest number, each player claims a revealed card and slides it into their grid to close the gap they created when they removed a card.
The starting player keeps rotating clockwise as players do this fifteen more times, eventually having a fully face-up 4x4 grid. Each number in a grid that's adjacent to the same number is removed, and the sum of the remaining cards is your score. Whoever has the lowest score wins.
Alternatively, play multiple rounds until a player reaches 100 points, then once again whoever has the lowest score wins.