Replayability in board games

In reply to a question on BoardGameGeek.

First of all, at some point I half-realized (and your post kinda forces me to try and flesh it out in words for the first time), that the word "replayability" can actually be understood differently by different people, that it's not super precise by itself. I see you did in fact seem to understand this, because you tried to elaborate on what you mean by that. Just to try and set the stage/context, IMO it can range the spectrum between, roughly:

⭐ On one end, basically every game being considered "replayable". ("Do we play the game again tomorrow?")
⭐ Then, the obvious first step away from this end being [b]"legacy games"[/b] - after you [family=80922][/family], you literally can't really play the game again with the same accessories; but truth said, you can still re-play the game (i.e. play it again), you just need to have another deck.
⭐ Then, I think I'd personally put generally your "typical" (however vague this descriptor is) board games; let's maybe call them [b]"one-shot"[/b] - everything from [thing=11901][/thing], [thing=11863][/thing], through [thing=2181][/thing], [thing=2399][/thing], [thing=171][/thing], to any and all most recent kickstarter etc. Now, all the entries below strictly speaking fall into this category (if you pause your chess game for a night, and come back tomorrow, is this a one-shot anymore? what if the one-night stretches to a month, because your opponent went to a vacation? what if you play the chess game over actual paper mail/letters, as was done historically? if you're playing in a chess tournament, isn't that a campaign with progression to become a world renowned chess Grandmaster?), but fancy me try and go with it further still in my approch; notably it's my first attempt at fleshing those out, so with high chance it will be messy...
⭐ Then, at some point, you get what I'm currently trying to call [b]"pre-scripted"[/b] games - IIUC e.g. [thing=255984][/thing], or basically most CYOA/Gamebook/paragraph games; maybe could be called "railroad" as well? - there's generally a "fixed" campaign you go through, that jumps from paragraph to paragraph of text written down by its authors like a book, usually doing something (more or less "playing the actual game") inbetween those paragraphs.
⭐ Then, arguably you might start entering what I try to call [b]"unique/precise oracle"[/b] "procedurally generated" games - parts of the storyline start getting randomized, but the random parts are "unique"/"precise", with specifically named one-in-the-world items/characters, as in "Gandalf the Grey", "Han Solo", "The One Ring", etc. If you destroy/kill/ascend/age the One Item/Character, any replayability still feels fishy to me - is The One Ring really The One, or are there more of them? Are we playing a parallel universe? To me, this kinda somewhat happens e.g. in [thing=193715][/thing] unfortunately, with your character being named specifically "Indulf Armiger", or in [thing=205637][/thing] with your character being e.g. "Roland Banks", etc. In the specific case of AH:LCG, I am trying to mentally force myself out of this fixation by arguing that the scenarios are "not real" but "repeated delusions/nightmares", but I find myself hard to convince about this really, unfortunately.
⭐ Next, IMO arguably you get to gradually less specific [b]"generic oracle"[/b] games. Here, instead of "Conan the Barbarian" / "Gandalf" / "Boba Fett" unique character, you are given a "class"/archetype of a "Powerful Barbarian", a "Wizard", "Space Bounty Hunter", "Ninja", etc. IMO, some games that fall more or less here include [thing=714][/thing] or [thing=146791]Shadows of Brimstone[/thing]. Maybe Mage Knight as well, I dunno, didn't have an opportunity to play it yet. I'd argue here we reach the games straddling/flirting with the boundary between "board games", "sandbox games", and "(pen-and-paper) RPGs". From the more RPG (or is it?) end, we get things like [thing=197097][/thing], [thing=418238][/thing]. Somewhere inbetween we also get e.g. [thing=788][/thing].
⭐ Next, arguably we're getting into the "pen & paper" RPGs territory: here, the rules themselves start becoming less strict and more amenable to on-the-fly tweaking (starting from "just some interpretation" in "simulationist/crunchy" RPGs like [family=17181]D&D[/family],  up to e.g. "deciding your truths" in [family=5891]PBtA[/family]/[family=68530][/family], or the thin veil of rules in various "one-page RPGs"), thus making each game arguably be kinda different game already.
⭐ Finally (?), games where the point is actually to modify the rules themselves - e.g. [thing=14451][/thing]. Arguably, the actual Real Life™ kinda too?

One question that might arise here, is at what point we stop/start calling a game a "board game"? or a "role-playing game"? or "a game" at all?

Given this attempt at an intro above, I would claim that two games I know that [i]might[/i] possibly try and fit your query - at least they kinda do so for me - are [thing=273654][/thing] and [thing=273655][/thing]. They have a lot of "procedural generation", and they use both "character archetypes" for your player agents and "generic oracles" in their scenario templates, plus quite a lot of randomization (arguably making them "fiddly", formally "ameritrash") thus allowing a lot of variety in replays. Yet still falling kinda into "board game" territory, which IMO means they have a finite set of "pre-made" physical components, which IMO OTOH necessarily means there's a degree of "sameness/repeatability" (the basic game loop is repeatable - walk a path composed of a finite set of increasingly-familar tiles; meet increasingly-familiar Encounters and Enemies; throw dice, fight, sometimes win, sometimes lose/flee). But they also provide some sense of progression: firstly, as in all SoB games, your characters "advance" (both in "levels" and "traits", as well as in "gear" and "afflictions"). But secondly, in those particular two games, the gamebook also provides an option of a "predefined campaign", which is notably arguably [i]not "pre-scripted"[/i]. This is done by suggesting to progress through a set of "scenario templates" (which are available in any SoB game and provide "high replayability" by being "generic oracles") in a specific order (which is unique to those two games), not being allowed to go to a subsequent "scenario" without winning in a previous one. And, this approach arguably can also provide a "sense of closure" if you like so, after completing the final "scenario" of the "campaign". The catch being whether you still consider it a "proper/serious/balanced/whatever board game". It's definitely and explicitly not an "eurogame", but an "ameritrash". It is "fiddly", "very random", "not very tactical", whatnot. A lot of your enjoyment may depend on whether you're ok with that, and maybe actually want that; and whether you find fun in stringing together some random events you happened to encounter during your playthrough into some vaguely coherent narrative - or, don't care to at all.

[i]Edit:[/i] To elaborate/clarify a bit more, I consider a single game may simultaneously be at various places on the same spectrum in its different aspects. For example:

● [thing=193715][/thing] has a lot of "precise oracle" elements (named characters; named Dungeon Lords), but also has some "generic oracle" elements (mist/debris/... Risk Cards; generic "minion" enemies; generic equipment like "Fine Sword" or "Magic Armor") on one hand, and some "pre-scripted" elements (the Campaign) on the other hand.

● the [i]Shadows of Brimstone[/i] series has a lot of "generic oracle" elements (archetypic characters; templated scenario elements like "blacksmith's son"), but occasionally has some "precise oracle" elements (e.g. some enemies, like "Sho-Riu the Dragon King" unique enemy - though it also has an alternate unnamed form; "The Ancient One" presumably - I don't have that expansion; named "Wasteland Warlords" in the Blasted Wastes expansion), and the Campaign in [thing=273654]SoB:VotSK[/thing] introduces some optional narration arguably crossing the border a touch towards "pre-scripted" (but it is still designed to be fully playable without those clearly marked paragraphs).

● the [thing=98527]Gloom/... of Kilforth[/thing] series of games has a lot of "generic oracle" elements (archetypic characters and enemies, randomized quest and Saga elements), but also some "unique oracle" elements (the map locations, the final bosses), and even some "one-off" elements (Kilforth/the-world itself - if you fail, "the world" is conquered by Gloom, so I find it hard to explain how it'd become de-Gloomed before next playthrough; it does have some optional "sandbox" rules disabling Gloom altogether, but I'm not sure if the character won't become too powerful too quickly in that case - but I must admit I haven't tried this yet).