Every jack that appears belongs to whoever slaps it first.
Snap with one rule instead of two, and no need to compare anything. Every jack that appears belongs to whoever hits it first.
A 52-card deck dealt out as evenly as possible, face down. Nobody looks at their cards.
Going round the table, each player turns their top card face up into a single pile in the middle. Turn it away from yourself so you do not see it first.
When a jack lands on top of the central pile, everyone tries to slap it. The first hand down takes the whole pile, shuffles it into the bottom of their own stack, and starts the next round.
That is the entire game.
Slap when the top card is not a jack and you pay the player who turned it one card, face down, from the bottom of your stack.
A player who plays their last card stays in the game for one more chance: they may still slap the next jack to get back in. Miss it and they are out.
The player who ends up with all 52 cards wins.
It is worth agreeing beforehand that the slap is flat-handed and on the card, not on the table or on anyone's fingers. This is the game most likely to end in an argument about who got there first, and the noise is most of the point.