Earlier today I posted a meaning-reversing typo in Stonehell: Into the Heart of Hell.
It's a meaning reversal because it tells you what you can't do, but ultimately, the book goes on to say (after 3 hefty paragraphs) that
"[. . . ] Stonehell is now yours to do with as you please."
I grew up with the AD&D DMG as my primary learning source. The book is full of admonishments about how to stomp on players who read the DMG. How to answer requests for monster characters (short version: No!) How to befuddle players who know how the game works. How I can't run a proper campaign without time records. Etc. etc.
There is definitely a right way to play, and a lot of wrong ways. It even says so in the introduction - change stuff, and it's not AD&D anymore. Tough talk to read when you're 10.
It's not just the DMG, though. I'm struggling to think of an RPG book that doesn't take pains to either tell you how to do it or else, or that it's okay if you change things.
Why is that? Why do we need special permission to change things? People mod the heck out of video games and we pop the cases on electronics that have sticky labels saying we're violating the warrantly. We jailbreak phones. We get LEGO sets and put them together into new things not shown on the box. We saw the heads and weapons off of minis and modify them, and paint them whatever the heck colors we want.
But RPGs always seem to have this section saying, it's okay to do this.
Board games don't, and we do it anyway (your money is under Free Parking). Workout books often go to great pains telling people not to change things, and they do it anyway (and then typically complain that their results varied.) People sample and re-mix music, without and without permission.
I'm wondering, just as a matter of writing, why we always feel like we have to say that it's okay to change things. Are we fighting a war of words with rules lawyer players? Are we figuring that our RPG books fall into the hands of people who need permission to change things? It's one thing to say, "It's up to you how to use this stuff, we haven't provided guidelines" but why do we need to give specific permission to change things?
Won't we all do it anyway?