TEXT: The Madey Upy Namey
  Emulator.
  I honestly don't have a good name for this GM emulator,
  like Tiny Solitary Soldiers or Mythic. I guess MUNE is
  good enough.
  Why play solo? How play solo?
  Have you been kicked out of your weekly game for playing
  an edgy jerk? Has your DM canceled due to crippling
  anxiety, again? Has a small meteor with the word
  SCHEDULING hit your house?
  And you still need to scratch that dungeon-roaming,
  character-building, monster-slaying itch? Then maybe solo
  D&D is the thing for you.
  "Duwahhh? You can't play D&D by yourself, moron.
  That's not how TTRPGs work."
  Why not?
  "Because you need a DM..."
  Ah, but you don't.
  At the end of the day, the DM is a game engine. They're the
  Unity 3D, the GameMaker, the Unreal Engine that runs the
  world. They set the scene, await player input, and make the
  the game react to those actions (or lack thereof). The
  function of a DM is highly complex, working on multiple
  levels to achieve a cohesive experience.
  But what if that could be simulated? Computer games try
  this all the time in games like The Witcher and Skyrim.
  They do pretty good jobs at creating linear stories for their
  players, but they could never hope to account for all the
  crazy things a player does in D&D.
  ... Or could they?
  Ultimately, a computer fails because it doesn't have the
  creative aspect that a DM does. We can't create artificial
  creativity; but we can borrow it.
  Second Hand Creativity.
  Imagine an NPC. If you're not thinking of a blank, faceless,
  mannequin-like entity, then props to you, you're not a
  typical player. Now change something about that NPC;
  maybe it's their occupation, an aspect of their appearance,
  a different race... That NPC is no longer wholly yours. It's
  been modified, changed ever so slightly at the behest of
  someone else.
  This is called second hand creativity, and it's the driving
  force of our emulated dungeon master, combined with the
  oracle system.
  The Oracle System.
  When we start out a campaign in D&D, we have a couple of
  expectations even before any of the details have been
  divulged by the DM; we expect that our characters are
  going to start at level 1, and we expect that we're going to
  start in a tavern (is joke, sort of).
  Take a look at this table for a sec:
  Oracle
  d6
  Answer
  1
  No, and...
  2
  No.
  3
  No, but...
  4
  Yes, but...
  5
  Yes.
  6
  Yes, and...
  This is the oracle. I can ask it questions as I would a DM.
  For example, I'm now going to ask if I start at the level 1. I
  roll a 5, so Yes.
  I also ask if I start off in a tavern; the result is "No, but...".
  I interpret this as most likely meaning that I at least start
  off in a populated area. I'd like to be sure, so I ask the
  oracle if that's the case; but this time the answer is Likely
  going to be yes.
  Likelihood.
  (For the longest time I used a complex system of modifiers
  to push a questions towards either Yes or No, but after
  having my eyes opened by u/lemunde I switched to using
  his concept and never looked back.)
  If you ask a queston to the oracle which is particularly
  Likely to return Yes, roll an extra d6 with your oracle roll
  and take the highest result. If the question is particularly
  Unlikely to return Yes, roll an extra d6 and take the lower
  of the two.
  Essentially, you apply advantage/disadvantage to the roll.
  For example;
  I ask if we start in a city, and roll two d6 because a
  positive result is Likely. I get a "Yes, but..."; something
  isn't usual about my situation.
  Maybe I'm not here of my own volition? I ask and
  receive a "Yes, and...".
  I ask if I've been captured as a slave. I receive a Yes.
  In four rolls we've gone from the bland startup of meeting
  potential adventure patrons in a tavern, to the much more
  exciting hook of escaping the captivity of some slavers. It
  could have started a myriad of other ways; I could have
  been imprisoned by the guards for some reason, I could
  have simply been visiting the city in order to earn some
  coin, or I could have even started in a completely different
  location.
  That's the beauty of second hand creativity; it's all from
  you, but you never know where it's going to take you.
  Interventions.
  Using the oracle system on its own is a perfectly viable way
  of playing solo, but there's so much more that can be added
  on top to provide a more fleshed out experience.
  1
  
  One of the first things to address is DM initiative. No, not
  the grab-your-weapons-and-tussle type of initiative. While
  the oracle modifies our expectations to take us places we
  could never dream of, it can never truly surprise us because
  we're always the ones asking the questions. Interventions
  simulate those moments when a DM springs a trap on us,
  introduces a helpful NPC out of the blue, or adds another
  ogre to the already huge pile of enemies to defeat.
  Whenever a 6 is rolled on an oracle question (including
  secondary dice if the question is Likely/Unlikely), you gain
  an intervention point. Keep track of them on a piece of
  paper or dice.
  When you've gained 3 intervention points, an
  Intervention occurs. Reset the points to 0 and resolve the
  nature of the Intervention using the table below.
  Intervention type
  d6
  type
  1
  New entity
  2
  Entity positive
  3
  Entity negative
  4
  Advance plot
  5
  Regress plot
  6
  Wild
  New Entity. A new entity appears. Maybe this
  introduction is beneficial to you, maybe not. The specifics
  can be gleaned from asking the oracle, with some potential
  help from a Portent (see below).
  Continuing to use our starting scenario, some examples
  of a new entity might see us encountering the head slaver, a
  potential buyer, or even a fellow slave with a plan to escape.
  Entities and Plots
  It can help to keep a list of entities and plots
  currently active in the adventure, adding and
  removing them as they become relevant or
  otherwise. This way you can simply roll on the
  list, instead of spending time asking the oracle
  what specific entity or plot an Intervention is
  referring to.
  Below are some helpful definitions of what the
  two of them actually are;
  An entity in the context of Interventions refers to
  any person or group of persons that are remotely
  autonomous, not simply specific NPCs and
  monsters. An entity might be;
  Old Jeph, the captain of the ship you hired.
  The elemental storming the king's castle.
  The town guards.
  A hooded stranger who's been stalking the
  party.
  A plot is an unresolved story hook or thread that
  usually acts as a goal of some kind. A plot might
  be;
  Discover the location of the lich's tomb.
  Pay off a debt to a dangerous crime lord.
  The seige of the town you're currently
  residing in.
  Resurrect a fallen friend.
  Entity Positive/Entity Negative. This is rather self
  explanatory. Something good or bad happens to an entity,
  the specifics of which can be determined by asking the
  oracle (with some optional help from a Portent).
  Again using our starting scenario as an example, some
  entity positives might include;
  Slavers: A top-paying slave owner is visiting town,
  looking to buy.
  Town guard: The guardsman at the town gates
  threatens to report the slavers for excessive cruelty,
  unless he's payed a "blind-eye" fee.
  Player character: You pass by a butcher's market stall,
  upon which lies an easily swipable carving knife.
  Some entity negatives might include;
  Player character: The journey to the village has worn
  you out, giving you one level of exhaustion.
  Player character: You are targeted by a whip attack from
  a slave driver.
  Town guard: A slave attempts and fails to steal a weapon
  from a guard, causing a commotion.
  Advance Plot/Regress Plot. This is also pretty self
  explanatory. Advancing a plot pushes an unresolved hook
  in a certain direction. An example of advancing a plot using
  the staring scenario might see the player rescued by a
  group of freedom fighters, and a plot regression might
  involve the player character being sold to a high-ranking
  city official.
  A plot advancement or regression should always help the
  the adventure progress, but it does so by either helping or
  hindering a certain goal or plot point.
  Wild. This is to simulate the completely unexpected. It's
  a catch-em-all Intervention that can be good, bad, neutral, or
  downright crazy. This is the option that allows for sudden
  twists of fate, such as a dragon swooping down to attack
  the village and allowing the slaves to escape in the ensuing
  chaos.
  Because a wild Intervention is so vague in what it can
  represent, you kinda have to use a Portant to figure out
  what the heck it actually means. Which brings us nicely
  to...
  Portents.
  A portent is essentially inspiration. It's a two word (or
  more) sentence that acts as a springboard for the
  imagination. Maybe you've got no clue what a particular
  Intervention should be, or maybe you've exhausted your
  ideas for why an NPC pulled you aside for an urgent chat.
  That's the time to use a Portent.
  Any random word generator will suffice for this. There
  are tonnes of these online, but a couple of my favourite are
  Watch Out 4 Snakes and Word Counter. I generally have a
  two-word generation limit, because I find that any more
  starts to get kinda messy, but you do you.
  For an exmaple, in our starting scenario a wild Intervention
  would require a Portent to figure out. The words I receive
  are "frail" and "jobbed". This could mean a bunch of things,
  so I get the oracle to narrow things down for me.
  I ask if a fellow slave looking very sickly approaches me
  for help; the answer is No.
  I ask if I get put to work doing a simple and easy job;
  No, but...
  Maybe I'm sold to a weak, elderly owner? Yes.
  2
  
  Portents can sometimes be quite specific in what they're
  referring to, but this is the exception rather than the norm.
  Most of the time the word combinations will be too random
  to directly apply, so instead you have to use them as a guide
  for your imagination.
  For instance, say I use a Portent to help me figure out what
  kind of monster I've encountered in a dungeon. I receive
  "delved" and "plutonium". The former immediately makes
  me think of a dwarf (or duergar), but plutonium is a little
  harder to directly fit into my D&D world. However, it does
  make me think of scientists and experimentation, which
  leads me to imagine a dwarven artificer.
  It helps to think of Portents as a game of charades, where
  the word you're trying to guess equates to how the Portent
  fits within the context of the scenario.
  NPC Interactions
  When crossing paths with an NPC, you generally have
  some idea of how they're gonna react. The prince will act
  lordly and noble, the beggar will ask you to donate to his
  charity, and the bandit will ask you to donate to his charity.
  But sometimes you turn up a loss at how an NPC is
  supposed to react.
  The first thing you want to do is determine their attitude
  towards you, which can be done with a simple d6 roll
  (using advantage and disadvantage as necessary);
  Starting attitude
  d6
  Attitude
  1-2
  Hostile
  3-4
  Neutral
  5-6
  Friendly
  Assuming the NPC stops to talk, the topic of their
  conversation can be decided by a Portent. It's really that
  simple. No smoke and mirrors here.
  Optimising Play.
  After playing solo for just over three years, across countless
  campaigns and two settings, I've found that there are a few
  things that can speed up and amplify the solo experience.
  Automated character sheets.
  Seriously, I don't know how I'd be able to play without
  them. Some people prefer the physical nature of a good ol'
  pencil and paper, but I urge anyone attempting to play solo
  to at least give an electronic sheet a try. Some good ones off
  the top of my head are OrcPub (for desktops), 5e Character
  Sheet (for IOS), and my personal favourite, Squire (for
  Android; well worth the price for the full version).
  Three strikes and you're out.
  When using the oracle system it can be quite easy to lose
  yourself in a maze of ands and buts, which can bog down
  the flow of the game. A good rule to use is that after 2 rolls
  on the oracle that result in an and/but answer, the 3rd roll
  ingores those modfiers and simply becomes yes/no.
  Ignoring the MUNE.
  Solo play requires a balance of sticking to the rules and
  knowing when to throw stuff out. Sometimes nothing
  springs to mind for the nature of an Intervention, and
  Portents can often make zero sense within the context of
  the current adventure. The solution to this is rather simple:
  Ignore them.
  These systems aren't infallable, after all; they're a bunch
  of random generators that you're using to build a cohesive
  and logical game. If you get an Intervention that truly
  doesn't make sense, treat it as though it never occurred. If a
  Portent is too obscure to find inspiration from, simply
  generate another.
  Subverting expectations
  The sample scenario is an acceptable way of putting
  questions to the oracle, but it's also pretty slow. We're
  putting forward highly specific questions to the oracle; "Do
  we start in a town?" "Am I captured by slavers?" "Does the
  town have a guard?"
  This is all well and good when you're setting the scene
  for the adventure, when nothing is certain (unless you wish
  it). But say my character walks into a tavern. I don't want to
  spend several minutes determining how full the place is,
  what kind of drink they serve, and whether there's the
  typical shady old man handing out quests. So I ask the
  oracle a single question:
  "Is everything as expected?"
  This can be phrased a number of different ways. "Does
  everything appear normal?" and "Is there anything of
  interest?" are some variations I often use. This essentially
  skips all the nitty-gritty of having to figure out each detail,
  while still leaving room for the oracle to shine.
  These questions are best used sparingly at the start of
  different "scenes" and location changes, and should never
  be Likeley or Unlikely in order to maximise the chance for
  the unexpected to occur.
  If the oracle answers no, and an alteration doesn't
  immediately springs to mind, you can use a Portent to get
  an idea of what's different compared to your expectations.
  Final words.
  There's no right or wrong way to play D&D, so long as
  you're having fun (and not encroaching on someone else's).
  These are simply guidelines, they're one man's way of
  playing. You play how you want, with who you want.
  And most importantly; like, subscribe, smash that
  paranormal activity button...
  3
  
  Chaneglog
  V1
  Created the thing.
  V2
  Switched around the results on the oracle table,
  because reading a brief wiki answer on how probability
  works, and then basing the table off that, was a bad
  idea.
  V3
  Changed some typos that somehow slipped past the
  rigorous proofreading process. No seriously, I spent like,
  a whole two minutes re-reading this thing once I'd
  vomited it out.
  
SOURCE: textdata/thevault/Solo/2. GM Emulators & Generic Solo Rules/The Madey Upy Namey Emulator (MUNE).pdf