If a fielder is injured or becomes ill during a match, a substitute is allowed to field instead of him, but the substitute cannot bowl or act as a captain. The substitute leaves the field when the injured player is fit to return. The Laws of Cricket were updated in 2017 to allow substitutes to act as wicket-keepers, a situation that first occurred when Mumbai Indians' wicket-keeper Ishan Kishan was injured in a match on 18 April 2018.
The captain is often the most experienced player in the team, certainly the most tactically astute, and can possess any of the main skillsets as a batsman, a bowler or a wicket-keeper. Within the Laws, the captain has certain responsibilities in terms of nominating his players to the umpires before the match and ensuring that his players conduct themselves "within the spirit and traditions of the game as well as within the Laws".
The innings (ending with 's' in both singular and plural form) is the term used for each phase of play during a match. Depending on the type of match being played, each team has either one or two innings. Sometimes all eleven members of the batting side take a turn to bat but, for various reasons, an innings can end before they have all done so. The innings terminates if the batting team is "all out", a term defined by the Laws: "at the fall of a wicket or the retirement of a batsman, further balls remain to be bowled but no further batsman is available to come in". In this situation, one of the batsmen has not been dismissed and is termed not out; this is because he has no partners left and there must always be two active batsmen while the innings is in progress.
Captive crickets are omnivorous; when deprived of their natural diet, they accept a wide range of organic foodstuffs. Some species are completely herbivorous, feeding on flowers, fruit, and leaves, with ground-based species consuming seedlings, grasses, pieces of leaf, and the shoots of young plants. Others are more predatory and include in their diet invertebrate eggs, larvae, pupae, moulting insects, scale insects, and aphids. Many are scavengers and consume various organic remains, decaying plants, seedlings, and fungi. In captivity, many species have been successfully reared on a diet of ground, commercial dry dog food, supplemented with lettuce and aphids.
The main objective of each team is to score more runs than their opponents but, in some forms of cricket, it is also necessary to dismiss all of the opposition batsmen in their final innings in order to win the match, which would otherwise be drawn. If the team batting last is all out having scored fewer runs than their opponents, they are said to have "lost by n runs" (where n is the difference between the aggregate number of runs scored by the teams). If the team that bats last scores enough runs to win, it is said to have "won by n wickets", where n is the number of wickets left to fall. For example, a team that passes its opponents' total having lost six wickets (i.e., six of their batsmen have been dismissed) have won the match "by four wickets".