Previous versions of the Spirit identified actions that were deemed contrary (for example, appealing knowing that the batsman is not out) but all specifics are now covered in the Laws of Cricket, the relevant governing playing regulations and disciplinary codes, or left to the judgement of the umpires, captains, their clubs and governing bodies. The terse expression of the Spirit of Cricket now avoids the diversity of cultural conventions that exist in the detail of sportsmanship – or its absence.
Crickets are hemimetabolic insects, whose lifecycle consists of an egg stage, a larval or nymph stage that increasingly resembles the adult form as the nymph grows, and an adult stage. The egg hatches into a nymph about the size of a fruit fly. This passes through about 10 larval stages, and with each successive moult, it becomes more like an adult. After the final moult, the genitalia and wings are fully developed, but a period of maturation is needed before the cricket is ready to breed.
Several types of cricket songs are in the repertoire of some species. The calling song attracts females and repels other males, and is fairly loud. The courting song is used when a female cricket is near and encourages her to mate with the caller. A triumphal song is produced for a brief period after a successful mating, and may reinforce the mating bond to encourage the female to lay some eggs rather than find another male. An aggressive song is triggered by contact chemoreceptors on the antennae that detect the presence of another male cricket.
Most male crickets make a loud chirping sound by stridulation (scraping two specially textured limbs together). The stridulatory organ is located on the tegmen, or fore wing, which is leathery in texture. A large vein runs along the centre of each tegmen, with comb-like serrations on its edge forming a file-like structure, and at the rear edge of the tegmen is a scraper. The tegmina are held at an angle to the body and rhythmically raised and lowered which causes the scraper on one wing to rasp on the file on the other. The central part of the tegmen contains the "harp", an area of thick, sclerotinized membrane which resonates and amplifies the volume of sound, as does the pocket of air between the tegmina and the body wall. Most female crickets lack the necessary adaptations to stridulate, so make no sound.
In the approximate centre of the field is a rectangular pitch (see image, below) on which a wooden target called a wicket is sited at each end; the wickets are placed 22 yards (20 m) apart. The pitch is a flat surface 3 metres (9.8 ft) wide, with very short grass that tends to be worn away as the game progresses (cricket can also be played on artificial surfaces, notably matting). Each wicket is made of three wooden stumps topped by two bails.
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.
A phylogenetic study by Jost & Shaw in 2006 using sequences from 18S, 28S, and 16S rRNA supported the monophyly of Ensifera. Most ensiferan families were also found to be monophyletic, and the superfamily Gryllacridoidea was found to include Stenopelmatidae, Anostostomatidae, Gryllacrididae and Lezina. Schizodactylidae and Grylloidea were shown to be sister taxa, and Rhaphidophoridae and Tettigoniidae were found to be more closely related to Grylloidea than had previously been thought. The authors stated that "a high degree of conflict exists between the molecular and morphological data, possibly indicating that much homoplasy is present in Ensifera, particularly in acoustic structures." They considered that tegmen stridulation and tibial tympanae are ancestral to Ensifera and have been lost on multiple occasions, especially within the Gryllidae.
If the match has only a single innings per side, then a maximum number of overs applies to each innings. Such a match is called a "limited overs" or "one-day" match, and the side scoring more runs wins regardless of the number of wickets lost, so that a draw cannot occur. If this kind of match is temporarily interrupted by bad weather, then a complex mathematical formula, known as the Duckworth-Lewis method after its developers, is often used to recalculate a new target score. A one-day match can also be declared a "no-result" if fewer than a previously agreed number of overs have been bowled by either team, in circumstances that make normal resumption of play impossible; for example, wet weather.
A match's statistics are summarised on a scorecard. Prior to the popularisation of scorecards, most scoring was done by men sitting on vantage points cuttings notches on tally sticks and runs were originally called notches. According to Rowland Bowen, the earliest known scorecard templates were introduced in 1776 by T. Pratt of Sevenoaks and soon came into general use. It is believed that scorecards were printed and sold at Lord's for the first time in 1846.
Crickets are small to medium-sized insects with mostly cylindrical, somewhat vertically flattened bodies. The head is spherical with long slender antennae arising from cone-shaped scapes (first segments) and just behind these are two large compound eyes. On the forehead are three ocelli (simple eyes). The pronotum (first thoracic segment) is trapezoidal in shape, robust, and well-sclerotinized. It is smooth and has neither dorsal or lateral keels (ridges).
Additional runs can be gained by the batting team as extras (called "sundries" in Australia) due to errors made by the fielding side. This is achieved in four ways: no-ball, a penalty of one extra conceded by the bowler if he breaks the rules; wide, a penalty of one extra conceded by the bowler if he bowls so that the ball is out of the batsman's reach; bye, an extra awarded if the batsman misses the ball and it goes past the wicket-keeper and gives the batsmen time to run in the conventional way; leg bye, as for a bye except that the ball has hit the batsman's body, though not his bat. If the bowler has conceded a no-ball or a wide, his team incurs an additional penalty because that ball (i.e., delivery) has to be bowled again and hence the batting side has the opportunity to score more runs from this extra ball.
The game on the field is regulated by the two umpires, one of whom stands behind the wicket at the bowler's end, the other in a position called "square leg" which is about 15–20 metres away from the batsman on strike and in line with the popping crease on which he is taking guard. The umpires have several responsibilities including adjudication on whether a ball has been correctly bowled (i.e., not a no-ball or a wide); when a run is scored; whether a batsman is out (the fielding side must first appeal to the umpire, usually with the phrase "How's that?" or "Owzat?"); when intervals start and end; and the suitability of the pitch, field and weather for playing the game. The umpires are authorised to interrupt or even abandon a match due to circumstances likely to endanger the players, such as a damp pitch or deterioration of the light.
Cricket entered a new era in 1963 when English counties introduced the limited overs variant. As it was sure to produce a result, limited overs cricket was lucrative and the number of matches increased. The first Limited Overs International was played in 1971 and the governing International Cricket Council (ICC), seeing its potential, staged the first limited overs Cricket World Cup in 1975. In the 21st century, a new limited overs form, Twenty20, made an immediate impact. On 22 June 2017, Afghanistan and Ireland became the 11th and 12th ICC full members, enabling them to play Test cricket.