What is it about football that makes it the most popular game in the world? Some would argue it's all about accessibility; while most other sports require a few items of specialist gear, all you need for a soccer game is a ball and a couple of bags or jumpers thrown on the ground to act as posts.
Others might say that it's the comparative lack of goals or points compared to say, hockey, basketball, or rugby, that makes those net-busting moments even more special. Some fans would say it's the passion that sets football apart — no one could argue with the fact that it's a sport uniquely capable of bringing out the fiercest emotions.
But sometimes those passions bubble over the surface slightly, both on and off the pitch. In a high-stakes game, it only takes half a second for things to get out of hand, and therefore, there are structures in place to make sure things remain organised and safe for everyone involved. Match officials play a vital role in keeping the peace, and while they have multiple tools and techniques in their lockers to help them with this, perhaps the most important of all is the yellow card.
In this article, we'll explore the role of this disciplinary aspect of football, explaining why players receive a yellow card in certain situations, and what the consequences can be. We'll also provide you with a brief history of this aspect of officiating the game, ultimately setting out why yellow cards are such an important part of soccer.
Professional fouls, mistimed tackles, unsporting behavior, dissent — as a soccer player, these are all things that can land you in trouble with the referee. Sometimes this will just mean a quiet word in the ear, whereas other times it'll be a harsher warning. However, if a misdemeanor is judged to be serious enough, the referee will be forced to take formal action. This is where the yellow card comes into play.
In soccer, a yellow card is given to indicate that a player or a team official (managers and coaches can also receive a yellow card on the sidelines) has been cautioned officially. The details of the offending person will be noted down by the referee, who will also make a note of the time and nature of the foul that's been committed. This moment, in which the ref writes down in a small notebook exactly what's happened, is what has led to the yellow card's most prominent nickname: the booking.
Sometimes, professionals will be shown a yellow card for incidents of misconduct that are accidental in nature, but that doesn't change the fact that an official caution needs to be made. Other times, bookings can be given for dangerous or overly aggressive play, a lack of respect for opposition players, or even improper celebrations — Romelu Lukaku's hugely controversial second yellow card against Juventus in the Coppa Italia (which was recently revoked) being a high-profile example of this.
When you get a yellow card, you're allowed to continue to be a part of the game, because unlike sports like rugby or ice hockey, there's no "sin bin" (a box or bench where offending players are sent for a set period following an incident) in association football. However, if a player receives two yellow cards in a single game, their second booking marks the end of their day; when a second yellow is handed out, the referee will immediately brandish a red card, meaning that the offending player or team official will be sent off, and banned from competing in that match any longer.
Shortly, we'll be looking at what happens in the long run when a player gets sent off, but first, it's worth fleshing out in a bit more detail exactly what offences can end up landing your name in the referee's notebook:
Unsafe or reckless play
Any offence (not only a foul) that interferes with or stops a promising attack
Showing dissent, i.e. protesting or disagreeing publicly with a decision made by a match official
Entering or re-entering the field of play without the referee's permission
Improper celebrations, i.e. removing your shirt or entering spectator areas
Entering the referee review area or excessively demanding a video 'review' in matches with VAR (video assistant referee)
Deliberately leaving the field of play without the referee's permission
Unsporting behaviour (this is up to the ref to judge)
Meanwhile, there's also a long list of offences that can land coaches and staff members on the touchline in trouble; these include disrespecting the confines of the team technical area, entering the opposition technical area, delaying the restart of play, disrespecting or showing dissent towards the referee, or being provocative towards opposition coaches.
As we've mentioned, if you commit any of the offences above once in a match, it's likely to result in a yellow card. If you end up receiving two yellow cards in a game and getting sent off, it won't just be your immediate situation on the soccer field that's affected.
When a player receives a red card in a football match, this on-field disciplinary action will result in a suspension from future matches. A match suspension essentially means a player or official is banned from taking part in said match, attending it within the area immediately surrounding the field of play, or communicating with match officials, players, and club officials. The length of the suspension can vary; when a player is sent off after getting a second yellow card, they will only be suspended for a single game. However, when a player receives a straight red card, the generally more serious nature of this offence means that they will be handed a three-match suspension rather than only missing one match.
In cases of dissent, a player will often end up with a two-match ban, and there's also the possibility of retrospective action being taken by football's governing bodies to hand out further punishment in hindsight. Players do have the power to appeal bans that they receive, but there's never any guarantee these appeals will be successful.
Cautions and dismissals have played an important role in association football officiating ever since the sport was formalised in the mid-late 19th century. However, in the grand scheme of things, yellow cards are actually a pretty new addition to the game.
Most people acknowledge that British referee Ken Aston was the first person to push for visual representation of cautioning in football. His campaigning for this change to football governance was partly down to his experiences in the 1962 FIFA World Cup, when he was unable to force Italy's Giorgio Ferrini to leave the field of play after being dismissed, due to a language barrier. Eventually, local police were forced to intervene, an event which highlighted the need for reform in this area of officiating.
But it wasn't until eight years later at the 1970 FIFA World Cup that the current yellow and red card system we all know was first adopted. Hosted in Mexico, it was the first professional competition that embraced Aston's idea for a colour-coded system, and it was a great success. In the coming years, the system was gradually implemented in all professional matches across the world.
Over the years, the number of yellow cards handed out in an average professional soccer match has increased, as officials have clamped down on the kind of rough, reckless tackling that used to just be part and parcel of the game in the 1970s or 80s. Football officiating has changed a lot — some would say for the better, others might argue that things have gone too far in the other direction. But throughout all the sport's transitions and changes, one small object has remained absolutely crucial to keeping the peace in football matches: the humble yellow card.
But the yellow card is just one tool that referees are able to use to keep control of a match. Communication with players, captains, coaches, and of course with the other officials is a central facet of the job, and often people underestimate the role that regular communication and explanation plays in professional football officiating.
For a deeper dive into the world of the referee — and their close allies, the assistant referees, the fourth official, and now the VAR (video assistant referee) — take a look at our article on game officials in soccer. It's packed with useful information about the specific duties and responsibilities of each official appointed to preside over an individual match.
And now that you have a stronger understanding of the role that yellow and red cards play in football, why not further expand your knowledge of how matches are ruled? Start by taking a look at our guide to one of the sport's most confusing laws: What are offsides in soccer?