I'm sure all of us have accidentally blundered into an awkward situation because we accidentally committed a social faux pas that you had never heard of before. Maybe you were standing on the right side of a moving walkway and didn't realize convention was to stand on the left to let people walking pass on the right. Multiplayer games often feature similar unspoken rules that a player must learn. For example in Team Fortress Two (a class based shooter) if you actually try to complete the objective on Hightower (a map in the game) you may end up being vote-kicked. This is because many people play that game mode just to mess around and get kills, and don't want the game to end by someone capturing the objective. It ends up being that often a player must learn all the unspoken rules of a game to avoid the ire of other players. This falls under the purview of what Tony Manninen calls Normatively Regulated Actions.
It is interesting to me, as often these norms are not unanimously decided, instead we have two groups arguing over a certain contentious issue. Manninen mentions camping as a contentious issue that many groups choose to ban, but we also see this in many other situations. The Team Fortress Two example I gave earlier is very contentious in the community; it isn't hard to find Reddit posts arguing about whether it should exist or not. ( https://www.reddit.com/r/tf2/comments/dyb8cr/end_the_no_capping_rule_on_hightower/ ) These arguments about what the norms should be Manninen calls Discursive Action. This establishment of what is and isn't acceptable can be found in any community surrounding a game. Much anger in the Smash Bros community is directed at players who crouch spam (called tea bagging in the community). The community surrounding the Blizzard CCG Hearthstone often labels certain decks as 'cancer' if they are powerful, aggressive, and a dominant percentage of the decks being played. There will then be some stigma associated with playing that deck. People will make fun of or even worse actively flame players who play the deck.
All of these examples of things not to do are not derived from the rules of the game, and often go counter to the rules and incentives of the game. Completing the objective is the mechanical endpoint of a match of Team Fortress Two, and there is no mechanical reason why a player would not want to play the deck with the best win-rate in Hearthstone. Thus the cultural norms surrounding a game are just as influential in player action as the game itself. This leads to a multiplayer community that is self-regulating to a certain extent. It is important as a procedural reading of a game cannot predict this sort of behavior. It is difficult to see only mechanically what players will find annoying and decide collectively to ban. This also isn't unique to multiplayer games only. Consider the Nuzlocke challenge in Pokemon games. A well known challenge in the Pokemon community with rules that people self impose on their own single player games. The rules were collectively decided, despite the fact that the challenge itself doesn't involve the game's multiplayer mechanics. These ways of playing a game are completely ignored by a procedural reading, and show the importance of playcentric readings.
I wonder why the procedural reading in certain games can take a greater role than others. For example, in Overwatch, we see playing the objective stay as the main focus for most players in the match. While the game may allow for creative fighting and creative ways of defeating other players, you are still following the rule of pursuing that objective. Now if I consider the game Ghost Recon Wildlands, when my friends and I used to play, we eventually got tired of the objective, and decided we'd rather spend our time blowing each other up with grenades when in most cases the game did not allow friendly fire. It's interesting how in these multiplayer objective based games, the pl…
At the end of the day, the most important part of video games is "the player and the play" i.e. the people interacting with the game and the way they interact with it. Sure the game provides a framework but it's up to the players to physically go around and do stuff so in my opinion it's perfectly acceptable, preferred even, when players ignore the "proper" rules of play in favor of their own rules of play. Not only does it mean that the game is robust enough to allow players to enjoy it in a way that wasn't necessarily intended, but it also means the audience enjoys the work enough to try and change it in some way, almost…
I wonder about your example of the Nuzlock challenge, you seem to look at how the players of a game set cultural rules for games. However are challenges cultural rules? You don't certain decks because they affect the meta, but a Nuzlock only affects you. Interesting read nonetheless.
I think player created rules are kind of interesting because they're meant to be contradicted. No capping is something people enjoy, but I think part of the fun comes from the deceptive intentions. It's fun as a community to break the developers intentions. But if no one ever trolled, would it be the same? Would we still feel that same sense of comradely if no one ever capped? I think not. It's kind of similar, with the decks in Hearthstone, we actively enjoy participating in this subgame with people we may not know all too well.