Fighting

Fighting is the most negative social interaction in all games in The Sims series. When two Sims dislike each other enough, they can start a full on fistfight.

When fighting occurs a cartoon-styled cloud of smoke will appear and obscure most of the fighting. Sims with higher Body or Athletic skill  skill are more likely to win the fight. A police officer and a burglar will fight if the police are summoned during a burglary.

The Sims
In The Sims, the cloud of smoke will completely obscure the fight.

If a Sim loses a fight, they will leave the neighborhood forever. Children can also have fights, but they will never leave town if they lose.

In The Urbz: Sims in the City, Fight can be chosen regardless of relationship.

As the Fight social type did not exist in The Sims and The Urbz: Sims in the City, Attack/Fight was a Mean Social.

The Sims 2 and The Sims Stories
Fights in The Sims 2 and The Sims Stories are a little more graphic and violent. Sims are now visible through the cloud of smoke, and will use a wide array of professional and comical fighting techniques. Sims with higher body skills are more likely to win fights.

During a fight, other Sims will react based on their personality. Mean Sims will taunt the fighters, nice Sims will be concerned, and shy Sims will run and hide. If one Sim cheers for a certain Sim in a fight, he/she is more likely to win.

Beginning with Nightlife, a fight can trigger fury. This can also happen in The Sims Stories.

If a Sim catches their children fighting, they will lecture the child.

After a fight, the Sims involved get a memory of winning or losing a fight.

In The Sims 2 and The Sims Stories, Attack is a Fight social instead of a Mean social.

The Sims 3
Fighting returns in The Sims 3 with a few changes. Besides high Athletic skill, Sims with the Evil or Mean Spirited traits are more likely to win fights. On the other hand, Cowards and Losers are less likely to win fights. The Martial Arts skill improves winning chances even more.

If a Sim wins a fight, they will receive the 'Winner' moodlet. If they lose, they receive the 'Humiliated' and 'Sore' moodlets.

Sims with the Mean Spirited trait may choose to "beat up" a Sim as well as use any Fight or Mean social.

If the Sim is not Mean Spirited, the social is "Fight". If the Sim has the Mean Spirited trait, the social is "Beat up". Like other Mean and Fight socials, the Sim can be kicked out if visiting. With Late Night, the Sim may also be Publicly Disgraced.