Lyxen
Great Old One
Personally I find the idea that you must have detailed and fiddly rules for anything forth doing dumbfounding. I mean have you ever been in a LARP? There often isn't basically any mechanics at all, it is just people talking and acting as their characters.
If I may, in our LARPs, we actually have quite a list of mechanics, based on code words, items, and abilities, which are used both for combat and outside of combat. For example, in a recent game I ran, one player used a "mental power" (whispered a code word and effect to another player) forced another one to overbid in an auction, getting all that player's money locked in escrow...

This is real time, to GM interruption, managed entirely by the players themselves, and it works really smoothly (although there are sometimes hiccups like the mage who did not understand that his sleeping powder had to be spread on the wind to "sleep" anyone it touched and who basically threw the little plastic bag containing flour at another player, to the hilarity of all).
We have tons of combat powers too, including spells and counterspells, "Battlemaster" powers (disarm, push back, dodge, etc.), knightly powers (powerful blow, fatal blows), various levels of magic and immunities, etc.
I sometimes wish that TTRPG fights could happen as dramatically and certainly as quickly as our LARP fights...

And look at the most famous D&D campaigns in the world, Critical Role. A large swathes of it is just people acting in character and immersing in the world.
Exactly, I know some people don't like the show and I confess having watched only the first few episodes, but this is the way we play (without the incredible voice acting of Matt and some others).