It's always something that I like to think about, because I'll admit it, I tend to laugh and make jokes about some pretty terrible things. I never actually feel like those events or tragedies are funny in nature, but the idea of actually making humor out of something so terrible is, from what I've observed, what makes those jokes funny. In other words, "Politically incorrect" jokes aren't funny because (Most) people find them to be true, they're funny because it's such a terrible thing to make humor out of, that some of us can't help but laugh at how ridiculous the context of the joke was.

Do you have a sort of mental system where you gauge if a joke is okay to make? What do you think is acceptable to make jokes about? What isn't? Is it a matter of context, who you're speaking to, or some other mix of things that makes a joke "Okay," or "Not okay?"

that's a good question

I think it just depends on my mood.

I don't draw the line anywhere on a good day, but on bad days, I draw the line at... jokes, period.

If there is a person present that will take serious offence to the joke and is also my friend. I don't like seriously offending my friends unless I genuinely believe what I'm saying, which I generally don't when talking about, say, WW2.

For me, it's when things get too personal.  Making fun of someone is okay if their okay with it, but if there's something that they're sensitive about, then it's wrong to make fun of it.

The line does not exist.

Usually intent and self-awareness.

When it ends up just being cruel. Like depriving children of food or making someone else's life a living hell for your sick kicks.

That's torture, not humour.

If my wife and unborn child were brutally raped and murdered.

Any topic can be funny, as long as everyone involved realizes it's a joke.

Depends on who your around and their sense of humor. I can joke about some horrible shit with close friends but get offended by relatively tame shit by comparison if it's strangers or people I don't know as well

With words/ talking, I can laugh at pretty much anything.

Anything physical is where I draw the line.

So no hiding a bucket of water above a doorway for when a friend walks in?

But really, it's less of a line and more of a blurry grey mess on a venn diagram.