Iosue
Legend
There's not much that I agree with Pedantic on, but I think he gets to the point here.I don't care for the framing as player entitlement, but I do agree with the premise for a specific framing of "gaming." Rule of Cool is usually a player forward means of shifting the structure of the game into negotiation. Players set out what they'd like to happen, GMs set costs or risks, and the currency added to either side is the perceived "coolness" favor by both parties.
I don't really like negotiation gameplay in general, and I think it's even worse when you're playing with a currency that has variable value to all the players involved in some incalculable, unknowable way. If there existed some other gameplay loop, where the players are presented challenges and leverage abilities, resources and some time/action economy to overcome them, RoC can break that, turning the same into a different, and in my opinion, worse game.
However, there exist modes of play that are entirely negotiation based to begin with, and RoC in those contexts is mostly just suggesting value should be assigned to the "coolness" factor when using them. If that's already the game being played, I have significantly less qualms, though I do like and way of formalizing its value, maybe using a boon/bane system, or meta currency.
IMO, "Rule of Cool" is absolutely necessary to run DM-based resolution in games. If a player suggests something that is plausible and/or feasible within the genre we are playing in, and furthermore is Cool, then denying it by strict application of the rules only encourages players to only engage in Rules Approved actions, and my game is impoverished by it.
That doesn't mean auto-success, though it can mean eschewing excessive checks.
I'm leery of describing it as "negotiation," as it calls up the hoary cliche of "convince the DM," and the reality is that there is not much DM-Player back-and-forth as "negotiation" implies. However, it very much relies on the players and the DM being on the same page with regard to genre, playstyle, and aesthetics.
It should also be noted that Cool is highly genre/playstyle specific, and thus can even be applicable to gritty survival-type games. (I daresay that most, if not all, gritty dungeoncrawl games have at one time or another made a call concerning flasks of oil that was not necessarily realistic or supported by the rules, but felt "right" in the moment.)