In cricket, a no-ball is a type of illegal delivery to a batter (the other type being a wide). It is also a type of extra, being the run awarded to the batting team as a consequence of the illegal delivery. For most cricket games, especially amateur, the definition of all forms of no-ball is from the MCC Laws of Cricket.
The delivery of a no-ball results in one run – two under some regulations – to be added to the batting team's overall score, and an additional ball must be bowled. In addition, the number of ways in which the batter can be given out is reduced to three. In shorter competition cricket, a batter receives a free hit on the ball after any kind of no-ball (see below); this means the batter can freely hit that one ball with no danger of being out in most ways.
No-balls due to overstepping the crease are common, especially in short form cricket, and fast bowlers tend to bowl them more often than spin bowlers.
It is also a no-ball when the bowler's back foot lands touching or wide of the return crease.
A delivery may be judged to be a no-ball by the umpire because it is dangerous or unfair, i.e. a fast short pitched delivery (a "bouncer") may be so judged, and any high full-pitched delivery (a "beamer"), or any deliberate front-foot fault (deliberate overstepping), is inherently dangerous or unfair.
Any beamer is unfair and therefore a no-ball, but the umpire may judge that a particular beamer is not also dangerous, and does not warrant a warning or suspension 
For deliberate beamers and deliberate overstepping, the bowler may be suspended from bowling immediately, and the incident reported. For other dangerous and unfair no-balls, or for throwing, repetition will have additional consequences for the bowler and team. The bowler may be suspended from bowling in the game, reported, and required to undertake remedial work on his bowling action.