Explaining the offside law can be a challenge, even for an ardent football fan.



But help is at hand after the Royal Mint published a diagram on the back of a 50p coin showing baffled spectators how it works.



The design is one of 29 produced to commemorate the London 2012 Olympic and Paralympic Games, each featuring a different sport, and could be a handy visual aide to explain the law without resorting to the time-honoured method of using salt and pepper pots to represent players.



Worth every penny: The London 2012 50p piece explains the offside rule

Limited edition: The commemorative 50p piece can be purchased as part of a special collectors pack from the Royal Mint

It is the first time in the Royal Mint’s 1,100-year history that members of the public have been allowed to design a series of coins for nationwide circulation.

Production journalist Neil Wolfson, whose offside design beat nearly 30,000 rival entries, said: ‘If I had 50p for every time someone asked me what the offside law was then I would be a very rich man.



'I hope it starts conversations.’



The offside law stops a striker lurking near the opposition’s goal for the whole match by ensuring he has to beat at least two opposition players, one of which will usually be the goalkeeper.



Daniela Boothman from Lancashire displays her winning coin, which represents volleyball

LAW 11: OFFSIDE RULE EXPLAINED

It is not an offence in itself to be in an offside position.



A player is in an offside position if:

He is nearer to his opponents' goal line than both the ball and the second-last opponent A player is NOT in an offside position if:

He is in his own half of the field of play

He is level with the second-last opponent



He is level with the last two opponents A player in an offside position is only penalised if, at the moment the ball touches or is played by one of his team, he is, in the opinion of the referee, involved in active play by:

Interfering with play



Interfering with an opponent

Gaining an advantage by being in that position

There is no offside offence if a player receives the ball directly from:

A goal kick

A throw-in

A corner kick

In the event of an offside offence, the opposing team is awarded an indirect free kick from where the infringement occurred

The coin uses triangles to represent the attacking team, and squares for an opposing goalkeeper and defender.



An attacker is shown about to make a pass to one of two teammates. The first is marked ‘Not offside’, as he is level with the defender when the pass is made.



The other is offside, as he is beyond the last defender.

The coin is already in circulation but can be bought separately in a limited edition presentation package on the Royal Mint website for £2.99.

'Neil Wolfson designed his coin in the hope that it would encapsulate football in a simple image,' the Royal Mint coinmakers website explains.

'As the offside rule is a perennial talking point, the image is designed to provoke discussion, which was what he was aiming for.'

Speaking about why he entered the competition to design the coin, Mr Wolfson said: 'I am a football fan. I've followed the Premier League since its inception.'

He said that designing the coin was an 'organic process' in which the most difficult part was getting the proportions right.



Other designs in the collection celebrate Olympic and Paralympic sports including swimming, boxing, gymnastics, boccia and goalball.

A panel of independent experts and representatives from Royal Mint, London 2012 and the International Olympic Committee picked the winning designs.



The London 2012 coins will be the Royal Mint's biggest joint release of designs on coins for general use.

Since its introduction 41 years ago when decimalisation was established, only 16 designs have featured on the nation's 50p.

The 50 pence pieces are the first British coins ever to be designed by members of the public

The coins in the above photo are as follows:



(Top row left - right)

Equestrian coin designed by Thomas Babbage from Shipston-on-Stour, Warwickshire



Weightlifting coin designed by Rob Shakespeare from Manchester

Boccia coin designed by Justin Chung from Manchester



Archery coin designed by Piotr Powaga from Pocklington, East Yorkshire



Tae Kwondo coin designed by David Gibbons from Matlock, Derbyshire

Shooting coin designed by Pravin Dewdhory from East London

(2nd row left-right)



Fencing coin designed by Ruth Summerfield from Stoke-on-Trent

Basketball coin designed by Sarah Payne from Cardiff



Cycling coin designed by Theo Crutchley-Mack from Pembrokeshire



Table tennis coin designed by Alan Linsdell from Manchester

Hockey coin designed by Robert Evans from Vale of Glamorgan near Cardiff



Handball coin designed by Natasha Ratcliffe from Falmouth, Cornwall.

(3rd row left - right)

Aquatics coin designed by Jonathan Olliffe from Witney, Oxfordshire

Wrestling coin designed by Roderick Enriquez from South London

Tennis coin designed by Tracy Baines from Peterborough

Modern pentathlon coin designed by Daniel Brittain from Derby



Canoeing coin designed by Timothy Lees from Stourton, Wiltshire

Goalball coin designed by Jonathan Wren from West London.

(4th row left - right)

Badminton coin designed by Emma Kelly from North London

Judo coin designed by David Cornell from Bexhill on Sea, Sussex

Sailing coin designed by Bruce Rushin from Norwich

Athletics coin designed by Florence Jackson from Bristol, David Podmore from Stamford, Lincolnshire,



Triathlon coin designed by Sarah Harvey from North London.

(Bottom row left - right)