does this kind of torture by bullies really happen..?

I can speak for a small area at a previous time, bay area, California between 1996-2001 and while there was a lot of bullying, none to the degree which is portrayed in this film, but certainly enough to make an already insecure teen mad enough to want to react the way they do in the film.

I was curious about what then did it mean when the movie said it was based on real events, is it just bad subtitles for me? the subtitles i have are not professional and i do not speak Estonian.

either way this is what they mean when they call a film haunting. gonna be awhile before i get this one out of my head.

Unfortunately, bullying is not uncommon in most school environments, but is usually mild in nature in comparison to the torture inflicted on Joosep and Kaspar. (I am talking in general - I am not too knowledgeable when it comes to Estonia in particular, but I doubt that bullying is unusually prevalent in the Nordic and Baltic countries).

I would say that such vicious bullying is extremely unlikely to occur no matter the school setting and the legislation that is in place....some of the aspects that I didn't find realistic:

1) Bullying is usually situational (it does not happen all the time) and there is an element of spontaneity to it...in "The Class", it appeared to be highly premeditated and the students seemed to be obsessed with it - it's as if there was nothing else that they could occupy themselves with and they plotted 24/7. I would be flattered (in a weird kind of way) if I was always the centre of attention and provided meaning to all these students' lives.

2) It's not likely that so many students would be willing to bully (or remain passive bystanders) and the girls would not enjoy it (and would tell a teacher or intervene).

3) Kaspar was initially part of the "inner circle" (that's my impression). It's not likely that a student like him (who does not seem like a geek) would be put on the spot and become a target just for stepping in. He may be teased a bit due to his willingness to protect the shy and quiet student, but all would be forgotten in a day or two (the bullies would not take his decision to intervene as a personal affront). Also, most girlfriends would appreciate Kaspar's compassion and would not break up with him due to his newly acquired "outsider" status.

4) Teachers and parents would not turn a blind eye to hardcore bullying and ringleaders like Anders would be expelled from the school (especially given that he brought a weapon on school property and threatened another student with it).

I wish people knew both how to handle it and how to get over it. So it doesn't in any way escalate to the extremes as such shown here!

I wonder which Southamerican country it was.
I went to pre-school until 3° grade of primary school during military dictatorship in Chile, then we got the "transition to democracy" and I finished High School in 99'. I attended a lot of different schools. I've witnessed bullying (at that time, it didn't have that name here), but I never knew of a case of such brutal abuse by a whole class, like the sexual abuse in Klass, that was way too much for me.
I can recall a girl being bullied in 2nd grade, she had special treatment by the teachers, she was older than us, so I guess most od the regular classmates were upset that she was "different" and treated her like an outcast. But we were barely 7 years old. Then I remember, after moving to other city, going back to the same school and some situations. But when I first started in a public school with thousands of kids, then I knew real bullying. A classmate I had, used to threaten the girls she didn't like and forced them to fight in the park outside school. She was the only one hitting, of course.
I was never phisically abused, people where affraid of me because I was punk rocker, but I was always treated like an outcast and I started to like being a misfit when I was like 13.

In a way, I can relate with Kaspar, because I've protected a few girls in high school, but not in a constant basis, just in specific moments. I never had to fight, but with a couple of sentences, I was able to make the dumb biatches leave alone the quiet ones. I was a quiet one too, but I looked way too strange for the average kids, I guess they couldn't deal with a smart, self-marginated teenage girl.

I knew a lot of Jooseps and Anders in my life. It is sad indeed.
Now in Chile, school violence it seems to be worst. We used to fight against the system, now kids fight against each other. You hear in the news about kids being stabbed by schoolmates or youtube videos of girls' gangs who beats one of their 12 years old girl classmate. It's terrible. But the level of constant and intense violence we see in Klass, I hope nobody ever experience that.

Please excuse my terrible redaction, english is not my native language.

I witnessed verbal and physical abuse all the time in Latvia. A lot amongst girls too, a couple of times saw a girl being punched by a group of other girls after school, she lost a lot of hair too. The most extreme I witnessed was when bullies broke a poor guy's hand. A guy I knew was bullied quite badly in the parallel class for a long time until he changed classes. At that point his confidence was zero, but luckily he made some friends in the new class and they protected him from the bullies. Was great to see his confidence slowly growing like a flower.
People usually skip a lot of school, or change classes/schools when bullied for a long time, so it doesn't turn out like in the movie.