Everyone "knows" this but it generally applies to more nuanced categories. For example, about liking your boss's jokes, believing in "Agile", etc.

But in regard to, you know, important stuff, such as matters of one's employment record -- you know they have ways of checking up on what you say, and that any company worth working for does exactly that -- right?

Again, I’ve never had this issue and never has anyone I know. They don’t call companies to ask if you were fired. They ask and tell you if you worked there and for what dates.

Reason for leaving is never told.

OK, so you're dodging the question, then.

"What to do if they ask question X?"

"Just lie, like everyone else does."

"Except you know that won't work if in fact they do ask you question X, right?"

"Doesn't matter, because they they won't ask you anyway."

Weird.

In any case it absolutely is standard practice for a significant portion of companies to go this route (especially in more traditional sectors). Even if it hasn't happened to you personally, or to people in your bubble world.

This is HN - the bubble of Silicon Valley and venture capital. I can tell you with great certainty it is incredibly uncommon to encounter people in HR who will tell you the reason why X person left the company. In a region that is happy to do lawsuits - they don't bother. After all - it's no longer their issue. They'll just verify dates of employment and that's it.

So definitely don't give the boss that fired you as a reference that they might call to check up?

Many employers make a point of checking the past 2-3 places on your resume, regardless of whether they were listed as references or not.

Also, not listing your most recent clients/managers as references (because why wouldn't they be glowingly positive?) can be seen as a red flag.