To set up the game you deal a no wild 57 Card deck out (removing the 57th Card) equally to everyone that is playing. Do not worry if one or more players have more cards then another.
The first player discards 1s face down into the middle of the table, the next player discards 2s face down, then 3s, 4s, … And so on until you get to 14s and then you go back to 1s.
When it is your turn you can put down as many cards face down as you would like as long as they are the right number. So if you are on 7s you can put three 7s face down and say “3 Sevens”. But what if you are on 7s and you don’t have any, hmmmm.
Since you are throwing cards face down you do not need actually throw away a 7. You can put a 6 and a 4 face down and call “2 Sevens”, as long as no one says anything your good.
But if you or someone else suspects someone of cheating you can say, “BS” or “I doubt it” or “cheat” and the other player has to flip over the cards they just threw down. If you were right and they were cheating they must pick up the entire deck of cards.
But if you where wrong and they actually threw away what they said then you have to pick up the cards.
Winning the BS game
The first person to get rid of their cards is the winner.
When you cheat make it small. No one will expect you of cheating if you only discard 1 or 2 cards.