What about accidental self-harm? i.e. the character runs into the road to escape smt or other, and gets run over by a car?

yeah the self-harm and suicide rules are far too strict, to the point of being absurd. I guess if your making family friendly safe (corporate) horror you can probably find something. It's just you can't do anything found in, Doki Doki Literature Club, Silent Hill 2's ending, Stasis, Dead Space, Silent Hill anything, Resident Evil, Happy Game, Paranoia Agent, Harry Potter, several ghost stories that are rated PG about 'hanged ghosts', Luigi's mansion, The cheese sauce scene in adventure time, hidden content in Five Nights at Freddies games... the list goes on to cover about 99 percent of horror and adjacent genres. Oh, and you can't do a story about Romeo and Juliet.

I suppose if your taking inspiration only from Disney movies in the last... no wait, there was a suicide in one or more of them, Coco I believe (as well as nightmare before Christmas) ... uh... Ok, so you can go super abstract with horror and focus on very small themes that do not personify people, like Can Your Pet, Carrots and Cream, um... there's probably more examples?

So it is possible to avoid using any of these themes. It's just a lot harder to get something that will resonate with people. I was kind of hoping the elaboration of the rules would be pretty open and include references like 'the ending to Silent Hill 2 is acceptable because it ties into the tragedy of the story and human condition' or 'if the story is about healing, or its a traditional zombie apocalypse it may be acceptable' but like, if you really think about it, I can't find many stories that don't have any of these themes outside of expressly strange, or expressly children's entertainment. Even the stories I was planning to put in here includes things like 'characters healing from an attempted suicide and finding a reason to live' or 'once you're infected with a brain-controlling mushroom, you either kill your family or... take yourself to pasture' 

So, I'd say just play on the side of SUPER DUPER caution if you planning to join the game jam. I unfortunately had to back out. All my ideas are going to be against the rules this year, maybe next year things will relax? we will see

Edit: you also cannot replicate several scenes/episodes/comics from my little pony friendship is magic... I'm not saying it's exactly good these themes are in every story ever, just that they deeply resonate with humans as a relatable experience/emotion

Thanks for laying out your thoughts, but I'm sorry to tell you the rules around these subject matters won't likely change.  

If you find yourself unable to write a Halloween themed story without encouragement of, instructions for and  on screen depictions of self harm and suicide, then this jam will likely never work out for you.