The whole thing is said to have been triggered by a so-called "rap battle" at the boarding school in January last year, with lyrics about, among other things, Hitler and prostitution.
Later, some masked students forced their way into two bedrooms in one of the dormitories and assaulted several younger classmates.
Värmland District Court has previously sentenced four male students to youth service for, among other things, assault and gross domestic violence.
The Court of Appeal for Western Sweden now largely upholds the verdict, but reduces the penalty.
"The Court of Appeal believes that the crime has a slightly lower penalty value than what the district court has concluded and therefore reduces the number of hours of youth service," the Court of Appeal writes.
The damages are also reduced slightly.
