One-day cricket differs significantly from first class cricket. A one- day match is played on a single day. Either a red or a white cricket ball may be used, and play under artificial lighting is allowed.

Each team gets only one innings, and that innings is restricted to a maximum number of overs. Usual choices for the number of overs are 50, 55, or 60. Each innings is complete at the end of the stipulated number of overs, no matter how many batsmen are out. If ten batsmen are out before the full number of overs are bowled, the innings is also over. If the first team's innings ends in this manner, the second team still has its full number of overs to score the required runs. The timing of the innings and the break between them are not regulated.

Whichever team scores the most runs wins. A tied score stands. There is no draw result. If the match is washed out, so that the innings are not played, the game is declared a no-result.

In each innings, each bowler is restricted to bowling a maximum number of overs equal to one fifth of the total number of overs in the innings. Either a single new ball is used for each innings, or two new balls which are alternated between overs. (This is often done with white balls because they wear much faster than red balls.) New balls are never taken during an innings, but replacements for lost or damaged balls are taken as in first class matches.

In case of rain interruption to the first innings, the number of overs for each innings is recalculated so that they will be the same. If rain interrupts the second innings, making it impossible for an equal number of overs to be bowled, the number of runs scored by the first team is adjusted to compensate. There is no standard adjustment formula - one is decided beforehand for any given competition. There is also a predetermined number of overs which must be bowled in each innings for any result to be considered valid; if this limit is not reached the game is a no-result.

Because of the emphasis on scoring runs quickly, wide balls are enforced much more strictly in one-day cricket.

One-day competitions are played either as Series between pairs of international teams, round-robin competitions between groups of international teams, or round-robins between domestic teams. A World Cup one-day competition is played between all the Test nations each four years.