Readers and writers, what makes a scene truly heart-breaking or emotional?

[ArthurAleksei]

The most important thing is the setup. You need to have fully realized characters that readers know and love, or else they might not care about something bad happening to them (perhaps this isn't always the case though).
The second thing, I think, is not to overdo it. Less is more, as the expression goes. I think a writer can go overboard trying to make a scene feel heart-breaking/emotional and it just falls flat. There's a fine line to be tread.

[Maps]

I try to step into my characters and what they’re feeling when I write so sometimes I can really FEEL their emotion and write about it. This is likely common. But there have been times where I’ve sort of emotionally overwhelmed myself while writing by just stepping into the characters mindset. I suppose that’s what acting can feel like?
But I feel like it evokes real feelings that might be relatable to a reader.

[domisotto]

Sad scene that guts someone takes a lot of prep. It has to be:

—relatable to the reader, not strictly personal experience of the writer
—the character must be under the reader’s skin by then
—the reader must believe that the character who is about to lose something truly loves having it or would give anything to have it
—there is no way to repair the damage

[GoldenHoneydew]

Anything- I'm a crybaby

[monotone_ink]

Hope

[HaltArrtay_RangerGod]

The connection between the two people in the scene.

[mrtoontastic]

The feeling of loss... that's heart-breaking to me. That and when a sacrifice made is truly noteworthy and hardhitting, especially when its a character is someone's who's been a motivation for you. Or someone you've looked up to, even when they haven't turned out the best in their later life.

[darthmongoose]

In my experience, first you need to have given enough specific detail about a character to make the audience buy into them as a person. It doesn't take much, but they need at least enough personality traits and life details to give that illusion of human lived experience rather than being an abstract concept.

And second, the thing that happens has to resonate with lived experience. There are some things that are universal, like say, experiencing the death of a loved one and missing them, the heartbreak of unrequited love, the drifting apart of childhood friends, a somebody reaching out with help or encouragement when you felt you were toiling along and unloved etc.

I think it's something you get better at as you accumulate lived experience. I think you can tell when the writer/artist has truly experienced a feeling or situation and is drawing on those feelings rather than just replicating how they've seen it portrayed in media.

[grotesqueice]

For me it's when someone does his/her best but still ends in bitter failure, regret or sometimes death.

[siluscomics]

I gotta be real attached to the character to feel emotional about anything that happens to them... That means lots of back story, and most of all I've got to be rooting for them!
The last book that made me cry was A Song of Achilles because when 'The Thing' happens, I was just so emotionally invested in the characters that I had to squeeze out a tear or two!

[allenT]

I‘m really lazy to write about how to make a emotional scene... I believe that to make a SCENE (any scene) one have to make deliberate setups.

Here's a video about how movies are put in efforts to affect audience's emotions, effectively.

Movie examples or not, the methods can work on every storytelling mediums. (novels, in some degree)

[Iris-Grimoire]

A lot of good points were given, and I think the main thing to keep in mind is buildup. Make the audience notice that if something bad happens, it's not only horrible or bittersweet for the characters, they are going to feel bad too. This is why a cheap gut punch feels that way; the reader telegraphed it as they should, but felt nothing from it. Make them feel like there should be a way to avoid this scene entirely, but deep inside they know there isn't.

[ArthurAleksei]

My favorite mangaka, Yoshitoki Ooima, uses this approach. She said she tries to get in the mind of each character when she draws or writes them. And judging from her works, it's an effective technique.

[ArthurAleksei]

Wow, Really good video.
The graphical side, of course, translates well to comics. But the main points work for any medium, like you said.