The score shall be reckoned by runs. A run is scored:

1st	So often as the batsmen after a hit, or at any time while the ball is in play, shall have crossed and made good their ground from end to end; but if either batsman run a short run, the umpire shall call and signal “One short” and that run shall not be scored. The striker being caught, no run shall be scored; a batsman being run out, that run which was being attempted shall not be scored.
2nd	For penalties under Laws 21, 27, 29, 44, and boundary allowances under Law 20.

NOTES ON LAW 19

1. If while the ball is in play, the batsmen have crossed in running, neither returns to the wicket he has left except in the case of a boundary hit, or boundary from extras, or under Laws 30 Note 1 and 46 Note 4 (vii). This rule applies even should a short run have been called, or should no run be reckoned as in the case of a catch.
2. A run is "short" if either, or both, batsmen fail to make good their ground in turning for a further run. Although such a "short" run shortens the succeeding one, the latter, if completed, counts. Similarly a batsman taking stance in front of his popping crease may run from that point without penalty.
3. 1. One run only is deducted if both batsmen are short in one and the same run.
   2. Only if three or more runs are attempted can more than one run be "short" and then subject to (1) above, all runs so called shall be disallowed.
   3. If either or both batsmen deliberately run short, the umpire is justified in calling "dead bal" and disallowing any runs attempted or scored as soon as he sees that the fielding side have no chance of dismissing either batsman under the Laws.
4. An umpire signals "short" runs when the ball becomes "Dead" by bending his arm upwards to touch the shoulder with the tips of the fingers. If there has been more than one "short" run, the umpires must instruct the scorers as to the number of runs disallowed (see note 1 to Law 4.)

Reproduction of the Laws of Cricket is by kind permission of Marylebone Cricket Club