Twenty20 Cup rules

1. All matches are 20 overs per side, with the teams divided into three groups - North (Derbyshire, Durham, Lancashire, Leicestershire, Nottinghamshire, Yorkshire), Midlands/West/Wales (Glamorgan, Gloucestershire, Northamptonshire, Somerset, Warwickshire, Worcestershire), and South (Essex, Hampshire, Kent, Middlesex, Surrey, Sussex).

2. Matches start at 5.30pm (although there might be some changes to fit in with television schedules), with a 15-minute interval before the start of the second innings at 7.00pm.

3. Each innings should last no longer than 75 minutes.

4. Teams will incur a six-run penalty if they fail to bowl the full 20 overs within the 75 minutes.

5. New batsmen must be in position within 90 seconds of a wicket falling.

6. Only two fielders are allowed outside an inner circle during the first six overs of a team's innings.

7. Bowlers are permitted a maximum of a fifth of the total overs in a completed innings (ie four overs if there is no delay or interruption caused by rain).

8. Umpires can impose a five-run penalty for time-wasting by batsmen. They are expected to be ready as soon as the bowler is ready.

9. No-balls will be penalised by a free-hit next ball with standard rules on no-ball dismissals applying.

10. Each side must face a minimum of five overs for a match to be valid. The Duckworth-Lewis method will be used to calculate run targets in rain-affected games.

11. The three group winners and best second-placed team will progress to the semi-finals/final day on July 19.

12. The overall winners will receive £42,000, the runners-up £21,000 and the losing semi-finalists £10,000 each.