System Mastery 257 – Mythic Roleplaying
Apparently what we have here is often considered to be the first stab at a DM-less RPG system! It’s from 2003, and boy is it unusual. How does it handle GM-less play, or many of the other things it’s stated to handle (such as being an overlay over your current RPG!)? Well, that’s what we’re here to find out, isn’t it?
System Mastery 
Not going to bat for the RPG. 100% agree with you on that one. I do kinda want to defend the Yes/No table though (otherwise known as an “Oracle” for modern GMless play).
When you play, if you don’t want an answer to a question, don’t ask it. The table is to help fill in things that aren’t obvious or when you want some random chance in something happening or being there. In the stairs example, if you want there to be stairs in a two story house, there are stairs and if you think it would be more interesting for there to not be stairs or for the stairs to be broken, then that is the case. You could want stairs in the house, but maybe you are unsure if you want them in the first room or not (maybe you are trying to find the stairs and you want to know if you move through some rooms before getting to them for possible encounters). When you open the door, you ask “Are the stairs in this room?” If you get yes, then yes, if no, then it is some other room. You can either determine where it is on your own, asking a clarifying question to the table (you can even ask a question that isn’t yes or no by asking the event table, either choosing one table and rolling or rolling both and interpreting the answer), or literally guesstimating how many rooms are on the ground floor and rolling a die to determine how many rooms you have to move through till you get to the stairs. If you get an exceptional yes or no, you can either interpret it, ask a clarifying question for what that means, or ignore it entirely if you have no clue (For me, exceptional yes could mean that the door literally opens to stairs and exceptional no could mean that the stairs aren’t in a room, they wrap around the back of the house on the outside).
You said that you don’t see the point of the table if you have to improvise things anyway as you can do that without the table, and I think you might be missing the point on this. Not everyone can do what you do and be satisfied with the result, especially if they are by themselves. The table is to facilitate an outside element that they can play off of. Of course its not as good as playing off an actual GM, but it can be better than no GM and it has lead to quite a bit of fun with my brother and I.
We used it to play pathfinder, with the only prep being character creation and an intial scenario. Our ship wrecked on an island along with a few other passengers. We found the remnants of other ship wrecks before us and other people trying to survive on the island. We encountered none to friendly natives that we tried to communicate with, but ended up having to defend ourselves as they tried to kill us. In the opposite direction, we found friendly natives, who made an actual attempt to communicate with us. What we could gather was that the island had two tribes, one who found love in community and spirituality and the other who loved to dominate others and make sacrifices to a mysterious god. The friendly tribe asked us to help save some members of theirs who got captured recently and if we could do that, they would help us get off the island.
Come to find out that not only did the “evil” tribe capture some of the friendly natives, but some of the survivors from our ship. Before they could be sacrificed, we barged in and took quite a few of the “evil” tribe members down. We freed everyone, but before we could get out of there a massive earthquake shook the island. Some of the surviving members of the “evil” tribe cursed us and told us that everyone on the island would be doomed in a couple of weeks time, as they sacrificed people to appease their god and keep them asleep. No sacrifice would mean the god waking up and destroying the island.
Out of character we figured out that the “god” was a massive creature slumbering beneath the island, and it was being kept asleep through an enchantment that was powered by sacrifices. We decided that maybe getting off the island was to be our priority, because there was no way we could fight that thing. We left off, headed our way back to the friendly village. (This was a simplfied version of all that happened, but you get the gist.)
This was done using common sense, the tables, and an encounter table for tropical encounters (for when our questions indicated a threat or some other encounter).
I think you’re meant to ask questions you would ask a real GM. Asking several seccessive questions regarding a door and door mat would probably get you chucked out of a game.
Every RPG going falls to pieces when you burrow into arbitrary details.