This section should help explain a real bear of the game of cribbage, muggins. I am not sure where the name came from or when it became part of the game, but it is the only optional part of the rules of cribbage for American Cribbage Congress tournaments and it is NEVER used at the Grassroots Clubs. Muggins is the practice of watching your opponent miss points during the game and then adding them to your own score. Points can be mugged from the two main parts of the game, the play and the show.
When the starter card cut is a Jack
OK, first, in the ACC, you can't mug a missed cut Jack. YOU can if your house rules permit, but not at ACC tournaments. The dealer can take the points for a Jack up until the time that they play a card, they don't lose the points when the pone plays. This is a simple rule to follow because the cut is not part of the play or show which is when muggins is in effect.
Muggins during the play
If someone pegs short it is easy to mug, point out the shortage and say "mug for 'x' missed the points here " and take them. For example, say that for making a 15 your opponent moves a peg one hole, and lets the peg go, you can mug the lost point.
If someone completely misses, say, a run in the middle of play, and you are to play the next card, it gets tricky. You have to give sufficient pause to give opportunity to take the points, but you can't play a card and then mug. If you play a card, the points are also lost to you.
If you see missed points but must say "GO", they have the opportunity, until they play another card, to claim the points. If you say "GO", and they peg the "GO", you can mug the missed points.
Muggins during the show
When the pone counts their hand and pegs the dealer can mug for missed points when the pone releases the peg. The pone can mug points from both the dealer's hand and crib. The pone must wait for the dealer to release the peg, if the pone is still counting the dealers hand and the dealer counts the crib and pegs it the pone has not lost the right to mug the hand. The opportunity is gone when the cars have been mixed back into the deck.
What is not Muggins
In all situations, if a person over pegs they lose the extra points and the other person gets the extra points, but only if the opponenet calls attention to it and has not pegged anything. However, if you notice that you have overpegged and you state the fact and correct it your opponent does NOT get the pointsMuggins is often left out of the qualifying round of ACC tournaments and then used in the playoff rounds. We don't play any muggins in the grassroots clubs because we are actually trying to teach the game more than let a couple people win. It kind of turns people off if their first time to a club they are continually mugged, being mugged once seems to fluster people and can slow down a game considerably. At the grassroots club level we may or may not mention it to each other when points are missed, it seems like more fun to me to win because I played smartly rather than because the other person has not learned to count everything yet.
Please feel free to email me with any questions you might have. I do enjoy corresponding with all cribbage enthusiasts.