B/X Known World
Because the rule-as-written sucks. If it’s something I can deal with or put up with it’s easier not to fight over it and play it straight. Any house rule will be a fight with some player, so unless I’d rather not play than play with that rule-as-written I’ll leave it.More specifically, what makes you, as a DM, sit down and change a rule?
Because I want to. It’s creative and fun. It’s also easier to invent lore than memorize someone else’s lore. And not having infinite time, I cannot be an expert in the lore of a world I didn’t create. Also, no one can correct me on the lore of my world. Less aggravation when you make it up as no one at the table will have spent more time with it than you and you can change details without arguments.What makes you craft different lore for your world?
Because they’re broken, don’t fit the world, or I’m tired of seeing the flavor of the month.What makes you not allow the presence of certain races, classes, backgrounds?
Power gamers and charop. 5E is already so ridiculously tilted in favor of the PCs just winning all the time that exploits and power gamer builds drain what little fun there is left in the game.What makes you not allow certain combos?
Money and who wrote it. I’m not going to buy every book and I don’t allow 3PP stuff in play. The WotC designers have a hard enough time avoiding power creep and most 3PP seem hell bent on broken stuff.What makes you use certain books and not use others?
The flip side of these questions can be put to players. Like why optimize in a game that’s already so laughably easy? Why write an epic backstory for a 0 XP, 1st-level character? Why insist on certain races, classes, or backgrounds?