Muggins, sometimes also called All Fives, is a domino game played with any of the commonly available sets. Although suitable for up to four players, Muggins is described by John McLeod as "a good, quick two player game".

Muggins is part of the Fives family of domino games whose names differ according to how many spinners are in play. Muggins is the game without a spinner, Sniff and modern All Fives have a single spinner, and, in Five Up, all doubles are spinners. However, historically Fives or All Fives was the progenitor of the family and had no spinners.

Muggins is characterised by its 'fives' scoring system, the 'muggins rule' and the fact that there is no spinner. The aims of the game are to domino, i.e. be first to shed all one's hand tiles, and, during play, to score points by playing a tile that makes the total number of pips on all endpoints of the layout equal to a multiple of five.