Out of all of the 42 laws governing the game of cricket, one stands out as the reason why cricket is still a reputable game - Law 42. Having been expanded over time to prevent all sorts of ungentlemanly behaviour, this law describes what is fair and unfair play, making the captains of the opposing teams responsible for their team's actions while giving the umpires the final decision on what should be done. If unfair play occurs, the umpire is usually obliged to inform some combination of the batsman, the captains of both teams and the other umpire of any decisions once they have been made, and will often report incidents to the appropriate governing body.
Awarding Penalty Runs
In some breaches of Law 42, the umpire will award five runs to the opposite side. This adds two more umpire signals to the game - the umpire will hold a flattened palm against the opposite shoulder to award five runs to the fielding team, and will pat his shoulder to award five runs to the batting team1. Penalty runs awarded due to unfair play are added to the total penalty runs for the side and do not affect the runs that can be given on the previous or next delivery; they will count fully even if the match has just reached its conclusion. If the batting team are awarded penalty runs on the ball that takes their last wicket and end up with more runs than their opponents, they are said to have won by penalty runs.
Apart from the instances covered by Law 42, five penalty runs can be awarded according to Law 41. Runs are awarded under this law if a fielder leaves the field with the ball and then returns without the umpire's permission, or if a fielder catches the ball with something other than a part of his body, or if the ball strikes a fielder's helmet which has been left on the ground outside the area directly behind the wicket keeper. However, if the receiving batsman is hit by the ball and had neither attempted to hit the ball or move out of its way, then no penalty runs can be awarded for that ball. The awarding of penalty runs in cricket is quite rare, as teams will usually take pride in maintaining the spirit of the game2.
Ball tampering has long been a controversial point in cricket, as it can give the fielding side an unfair advantage. When a ball is new, the bowler can shine one hemisphere of the ball while letting the other side become naturally damaged. The different aerodynamics of the two sides makes the ball swing in one direction, making the ball more difficult to hit. However, the shine is soon lost and the fielding side must wait until the ball deteriorates further before it will begin to swing again. The ball is eventually replaced, and so some bowlers are sometimes tempted to increase the rate of deterioration so that they can bowl with an inswinging ball for longer and to greater effect.
Although players are permitted to shine, dry and spit3 upon the ball, actions such as rubbing the ball on the ground, picking at the seams and using implements to damage its surface are all banned. Players are not allowed to remove grass or mud from the ball without the umpire's supervision. The umpires must make frequent and irregular checks as to the ball's condition, with five runs being awarded to the batting side and the ball replaced with one which would have comparable wear to the current ball had it not been tampered with. If the incident is repeated, five more runs are awarded, the ball is replaced once more and the current bowler is banned from bowling for the rest of that over.
If any member of the fielding side deliberately distracts the striker4 by either action or word, the ball is declared dead5 and has to be repeated, with the fielding side being warned. If the same happens again, five runs are awarded. Meanwhile, if a batsman is distracted or obstructed after hitting the ball, five runs are awarded but the ball is not called dead and the batting side keep any runs they gain, including the run in progress, whether it is finished or not. Neither batsman can be out from this ball, which will not count as part of the current over. The two batsmen must finish with the run they were obstructed upon, but are then allowed to decide which of them will face the next ball.
The offence of a batsman obstructing the fielders is covered in rule 37, which states that the batsman may be given out for 'obstructing the field' if such an event occurs.
Dangerous and Unfair Bowling
Some forms of delivery are banned and a bowler may not bowl in these ways regardless of the protection the batsman is wearing. If such a ball is bowled, the umpire will call a no ball and caution the bowler. If there is another incidence of dangerous or unfair bowling by the same bowler in the same innings, the bowler is given a final warning, with a third offence leading to the bowler being banned from bowling for the remainder of the innings. Another bowler must step up to bowl the rest of the over, with the conditions that the new bowler has not bowled in the previous over and will not bowl in the next. In the case of an intentional high full-pitched ball, the bowler is given no second chances and must stop bowling immediately. The following balls are deemed dangerous and/or unfair:
Fast short-pitched balls (these are balls which bounce nearer the bowler and can gain more height before reaching the batsman) liable to injure the receiving batsman.
Fast short-pitched balls which would pass over the standing head height of the batsman.
High full-pitched balls (these are balls which do not bounce between bowler and batsman, a delivery known as the 'full toss') which would pass above the standing shoulder height of the batsman.
Fast high full-pitched balls which would pass above the standing waist height of the batsmen.
It would be disastrous if teams were able to waste time in order to avoid losing a Test match - imagine a team trying to spend a whole day minimising the number of overs bowled, and you will immediately understand the need for a rule against time wasting. It is possible for both the batsmen and the fielding side to delay play, and so there are rules governing both:
Fielding side - if the fielding side wastes time or an over is unnecessarily slow, the umpire will warn the captain of the fielding side. If any further time-wasting occurs during the innings, the umpire will ban the current bowler from any further bowling during the innings. If this is not possible due to the time wasting occurring between overs, five runs will be awarded to the batting team.
Batting side - if a batsman wastes time by not meeting the requirements of other rules, the umpire will give one warning, with a second occurrence leading to five runs being awarded to the fielding side. As above, the warning applies for the entire innings, with each new batsman being warned of the caution.
Damaging the Surface
The protected area of a cricket pitch is a rectangular area which sits in the middle of the pitch, extending to a point five feet in front of each popping crease6 and two feet either side of the centre line joining the two middle stumps. If the bowler runs on the protected area a dead ball is called and the same procedures are used as for a case of unfair bowling. If the fielding side cause any other form of avoidable damage to the pitch, they are cautioned once, with a repeat of the incidence during the same innings leading to five runs being awarded to the batting side.
Meanwhile, if either batsman causes avoidable damage to the pitch, they are cautioned once. On the second occurrence, the umpire will give a final warning and cancel all runs from that ball except for penalties due to a no ball or a wide. On the third repeat, the runs are cancelled in the same way, and five runs are awarded to the fielding side.
It is technically feasible for the batting side to steal an extra run while the bowler is running up, but this goes against the spirit of the game and is therefore outlawed. If the bowler does not run one of the batsmen out when they steal a run, then the umpire will call a dead ball as soon as the batsmen cross in the middle and will order the batsmen back to their original ends. Meanwhile, the bowler is permitted to run out the non-striking batsman if they leave their crease before the bowler enters his delivery stride, with the ball not counting as one of the over in such an occurrence.
Law 42 also allows umpires to intervene in other cases of what they deem to be unfair play, and will also report players who act against the spirit of the game. These offences are covered by the Preamble to the Laws, and include:
Disputing the umpire's decision
Advancing towards the umpire in an aggressive manner
Use of abusive language
Distracting your opponent under the guise of enthusiasm or team motivation
Appealing when a player is obviously not out
Appealing for longer than is really necessary
Any form of violence - there is absolutely no room for violence in cricket, and there never will be
The captains and umpires are expected to set a good example, and all the players should follow and contribute to the upholding of the spirit of the game7. After all, it just wouldn't be cricket if they didn't.