As I recall, the game was basically crazy eights. You can look up the rules in any card book. The specail part was what was done after the game was over. I used to play with my brother only so I am not sure what happened for more than 2 players. You counted up the number of cards left in the losers hand. You then cut the deck and if a red card came up, the knucks were hard, a black card called for soft knucks. I remember that you hit the knuckles with the flat deck for each knuck. There were other variations, I seem to remember scraping knuckles being worth 5. One significant feature is that if the winner got carried away and dropped any cards, he got knucks for each card dropped (52 if the whole deck dropped)