With hand mucking, the quickness of the hand deceives the eye. A hand mucker will normally work alone with some agility and a poker face.
Muck in normal terms is mess, rubbish or anything which you might want to throw away. In poker terms muck is a piles of cards which is discarded, when a player folds or throws in his cards, the hand, or group of cards, which is abandoned is known as muck.
Hand mucking occurs when a player deliberately retains a card for later use in the game. The card will be concealed or hidden, thus it is secretly withdrawn from the game. Well, you might ask how does that happen without detection? It is a well practised sleight of the hand. Normally, when hand mucking the offending player will conceal the removed card in a pocket, under a leg, up a sleeve, or even under the table.