I love beating dead horses!
In reply to the claim that my #1 house rule "doesn't change anything about the characters in-game", I really must disagree.
It changes the character's' in-game options, that is, their paths of fate. Whichever road you travel definitely affects you. The same goes for characters in-game.
Back to the sleeping dragon... Choosing to go to its cave rather than hunt goblins would most likely have vastly different consequences for the characters. And death qualifies as a major change, I would say.
And though the rule doesn't change game mechanics, it does profoundly change game content. Such as scenery, encounters, plot-lines, conversations engaged in, etc. In short, role-play. Making the rule central to the game, as played by the players and their DM.
DnD has many kinds of rules, including games mechanics, etiquette, dungeon design, campaign administration, etc. None of these categories has a monopoly on "house". The house may customize any or all types of rules pertaining to the game.
That's what makes them "house" rules.
transcendation