Am I doing 5e wrong!

[KorvinStarmast]

@narsil
He was referring to a picture on a box that held the Holmes game. I still have it.

This is a nice history, but it doesn't support your assertion that all editions prior to 3.x did not allow house rules.

Nothing can, because house rules were the habit, not the exception, in the early going.

NewDM is Dead Wrong.

Back when D&D was new, they almost never used house rules. They were more like military exercises requiring precise execution to work properly.

Dead Wrong Twice.

Since I played Chainmail, OD&D, Holmes, and AD&D 1e A Lot -- Moldvay/Mentzer, 2e a bit -- I actually know how they worked and where folks used to fill in the blanks. {scrubbed}

1. In the 1st edition of AD&D, the DMG explicitly encourages DMs to house rule. E G Gygax brings this up time and again in his various expositions in that tome.

2. The foundation for house rules as the norm were laid In The Beginning.
See Wilderness and Underworld Adventures, TSR, 1974, Gary Gygax and Dave Arneson, Volume 3 of OD&D, page 36. Italics and bolds added by me to spell it out more clearly.

AFTERWARD:
There are unquestionably areas which have been glossed over. While we deeply regret the necessity, space requires that we put in the essentials only, and the
trimming will oftimes have to be added by the referee and his players.

We have attempted to furnish an ample framework, and building should be both easy and fun. In this light, we urge you to refrain from writing for rule interpretations or the like unless you are absolutely at a loss, for everything herein is fantastic, and the best way is to decide how you would like it to be, and then make it just that way!

On the other hand, we are not loath to answer your questions, but why have us do any more of your imagining for you? Write to us and tell about your additions, ideas, and what have you. We could always do with a bit of improvement in our refereeing