Present-day D&D practice may not admit of a procedural manual, but ours might, no?
An initial chapter might explain the importance of having a place that you control as the game venue (generally your own house), explaining why playing in a public place is liable to have too many distractions, as well as giving advice for keeping the fridge stocked, ordering food ahead of time and all that jazz. Simple stuff, yes, but things that a noob might not think to do for an art form with a strong component of people management.
That last needs a whole chapter too: Paying attention to players' emotions. Stepping in to resolve conflicts that are getting out of hand w/ techniques like making everyone go for a walk to cool down tempers. Praising players for good planning, good cooperation, clever use of abilities.
As a work sample for a job application, I spent some time writing a Python library which lets a game designer create basic text adventures. Though the library is a mere prototype, I was able to use it to implement a sample game called "Bread Master."
My library and its documentation are available on my public GitLab account. The rest of this page reproduces some introductory sections from the library's README, as of 2020-05-09.
I propose a videogame with two modes. Mode 1 is played in a 3rd-person or 1st-person perspective (I think 1st-person would be more satisfying.) On your turn, you swing your sword toward the enemy's body. The motion of the sword can be precisely controlled, as can the hit location; part of the game skill is hitting a "juicy" place on your enemy.
If you were transformed into a wooden cylinder,
transported to the highest point of your current location,
and dropped so that you rolled,
would you like where you ended up?
You've overlooked all the colors of flavor: all 16 million of them!
D
To be precise, (16^2)^3 = 256^3 = 16,777,216 colors, if we're talking about RGB colors with two hex digits to specify each channel, e.g. FFAABB.
There's a connection here with wagon wheels. The following code is semi-pseudocode for Inform 7.
From 2018-10-01 to 2019-02-01, I created an adventure videogame based on the life of my friend Ryan Wright, an American who is studying game design in Copenhagen. The game has been enjoyed by all who've played it, including the titular Ryan.
estimated play time: 1-2 hours (too long? Try the five-minute Fedoradventure.)
difficulty: easy/medium. An UNDO command is included.
The game is usually played by one person, but friends have found it even more entertaining to play as a group: everyone suggests things to try next, and one person does the typing.
My friends team up to play Ryan Quest during the final beta test.