RPGMemes

There's "everything goes exactly as planned until one player derails the whole session unhindered by rolls or turns" rules-light and "let things flow more naturally and allow things outside the rules if everyone thinks they add to the story" rules-light though...

Personally I much prefer the presence of rules which can be followed if convenient or desired, or ignored if you'd rather, but it is also equally valid to want to do collaborative storytelling/investigation without being derailed by bad rolls, I just know that dealing with setbacks and things not going to plan (which is different to things not succeeding in a pre-planned manner, but again equally valid, along with everything going well if you'd rather) is probably my favourite part