So, I know that according to MLB rules, the umpire in chief can forfeit the game if an ejected player refuses to leave the field.
Can a soccer/association football referee forfeit a match the same way?
Say a player gets red carded, and decides to stand and keep arguing. Can referee forfeit the game if he doesn't leave or does he just keep slapping the player with more red cards?
This situation is covered in Law 5 - The Referee, Section 3 - Powers and Duties:
The referee:
...
- stops, suspends or abandons the match for any offences or because of outside interference
If a sent-off player refuses the leave the field of play and the match is unable to continue as a result, the match is abandoned, and this is reported to the competition administrator.
The referee has no power to declare a forfeit - they simply report the facts of the match, and the competition administrator makes a determination on the outcome in accordance with the competition rules as stipulated in Law 7 - The Duration of the Match, Section 5 - Abandoned Match:
An abandoned match is replayed unless the competition rules or organisers determine otherwise.
Based on personal experience, if a sent-off player causes a match to be abandoned, the competition administrator would take a very dim view of this. It is likely that the sent-off player's team would forfeit the game, and possibly be fined and lose competition points. The sent-off player would most likely face a lengthy suspension (in addition to that imposed for the sending-off offence).
Under the current IFAB Laws of the game a referee has the authority to stop, stop, suspend or abandon the match for any offence or because of acts of outside interference. Unlike the MLB Baseball Rules Book, this doesn't directly decide the winner of the match in of itself, with the relevant section stating that:
5. Abandoned Match
An abandoned match is replayed unless the competition rules or organisers determine otherwise.
In many competitions it's likely that an event like failure to control their players to the extent that a match had to be abandoned would lead to it being declared a victory for the the opposing side, with a 3-0 scoreline often being declared as the result. This will be part of the individual competition rules however. rather than the general rules of the game.
As the IFAB Laws of the Game - Law 3: The players - Extra Persons on the Field of Play states:
The coach and other officials named on the team list (with the exception of players or substitutes) are team officials. Anyone not named on the team list as a player, substitute or team official is an outside agent.
If a team official, substitute, substituted or sent off player or outside agent enters the field of play the referee must:
- only stop play if there is interference with play
- have the person removed when play stops
- take appropriate disciplinary action
Usually, sent-off players will argue with referees after being sent off but eventually they will leave the field. What we see more frequently is some spectators (outside agents) running onto the field and being removed by security guards. Even if the guards don't explicitly ask permission from referee for removing the outside agents, they act according to the aforementioned law of the game.
The same would apply to the sent-off player, who will be removed by security guards in case if he doesn't want to leave the field, because the previously mentioned law applies not only to outside agents but also to sent-off players.
So, to answer your questions:
Can a referee forfeit the game if the player doesn't leave?
No, he'll just have the person removed with the help of security guards.
Does the referee just keep slapping the player with more red cards?
No, there's no point of showing multiple red cards, because the referee can just add the player's behavior to his protocol, so that the competition body could take appropriate measures later. This question has been already discussed here.
