On the low end maybe you just integrate it into some future DLC, and the unlock method as it exists now is treated as an early access bonus?

yeah I suspect this is what they're ultimately planning on, in a few months. if you're careful about it, you could even do this while preserving the fun of the puzzle -- let most people spend some sizable but attainable sum of in-game currency to unlock the class the simple way, but also allow the devoted to continue to do it the old way by [spoils myself on how to unlock this one] equipping these 10 specific items and unlock it for free.

I was going to say that perhaps the class unlock requirements could be randomized to some degree, but upon further consideration I think that will just end up creating more elaborate steam guides for the dedicated players, while more casual players will either stumble into it as intended (in which case was an elaborate set up required?) or they will find it in the guide and think it's too much work.

Guild Wars 2: Path of Fire launched with several mounts marketed as features for new players, but they didn't market a secret fifth mount that players discovered the questline for after completing the story quests.

I could see some version of "deep secrets" being hidden on a generated, personalized-per-player basis, if the actual secret was part of standard gameplay and not an ARG.

Like, imagine a game the size of Tears of the Kingdom, with dialogue or notes that hint towards a deeper, larger quest, a treasure hunt, a world-spanning puzzle; each game cart with its own randomly generated locations involved, where the hints appear, the pieces it's built out of. This would make it... guide "resistant", at least, but only to an extent. It also sounds like an incredible amount of dev resources to spend on something very few will see - to build a system that could lay these out reliably - but I think the fact that discovering something so large is hidden is often what makes it feel so amazing.

This reminds me of the small puzzles and easter eggs that are hidden in MMOs. I remember WoW having quite a few of these... in the earlier days, they would be discovered bit by bit by random players who happened to stumble across them, but over time they became so ubiquitous and extremely ornate that people formed extremely dedicated puzzle-solving groups to piece them together, racing to solve them, and then those secrets would become part of common knowledge online. Once it's solved, it's solved. FWIW, I think there's still some fun as a player just following the huge guides that take you around the world, as a form of participating in the secret without needing the dedication to immerse yourself in it.

I have a hard time thinking of a solution to this that doesn't involve random generation of some kind, and I don't know how fun that would actually play out in execution...

Examining the Binding of Isaac ARGs in this light is kind of interesting, with two different approaches for upkeep past the sell-by date of the ARG. At launch, the game featured an item that seemingly did nothing called the "Missing Poster". If you died in a specific room while holding this item, you'd be given a puzzle piece, one of multiple hundreds, that when pieced together, detailed an incredibly convoluted set of steps of dying to specific enemies in specific floors as specific characters, which would unlock the secret character.

However, no one actually went through the effort of completely putting the puzzle pieces together, as someone datamined the answer within 4 days of the game coming out. There was a bit of a brouhaha in the community as the devs publicly expressed disappointment with the dataminers spoiling the puzzle in this way.

When the first expansion came out, the unlock condition became simplified to the first step of dying with the Missing Poster. Considerably less tedious of a process and potentially discoverable without outside information, but still a bit obtuse.

The materials of the second ARG were done outside of the game to prevent datamining, and eventually culminated in the players "giving [the new character] a voice" by discovering the log-in details of a twitter account and tweeting things onto it, at which point an update was pushed allowing people to unlock this new character by giving enough money to the donation machine at the end of a specific mode.

Considering the donation machine already had several other unlocks tied to it even prior to the ARG's completion, its a pretty natural thing to discover playing on your own now, but it bears no attachment or reference to an ARG having occurred at all. You wouldn't know it was tied to this unless you looked it up on a wiki.

I personally don't think either approach is perfect, (one is still a little too obtuse and the other doesn't preserve the spirit of the original journey) but you can see them have some consideration for the play experience years down the line.

One of the only easter eggs that I remember many years later was the way that Dungeon Keeper had an extra level that was only accessible on a full moon. Relating it to something in the real world environment felt really interesting to me at the time and I don't think it's something many games have built on.

While I'm not a game designer, I can speak as someone who enjoys ARG type puzzles, but often comes to them pretty late after they're already done.

I think it's possible to design your ARG in a way that the trail can be followed exactly the same way, no matter if someone is trying to solve it on day one or five years later. Obviously this can be difficult to do and limits what sort of puzzles it involves. I think latecomers especially don't mind looking at a guide to see where to start and trying it on their own from there. My favorite example of this is actually the Altador plotline from Neopets lol. The only long term concern with that was the continued hosting of the secret webpages. Well... and the death of Flash, but that was a Neopets-wide problem...

Ultimately though, I think a lot of the point of ARGs as a genre is the communal "you had to be there" experience. I think game designers shouldn't necessarily feel the need to keep it perpetually available if it doesn't seem feasible. I don't know the details of Remnant 2's ARG, so I don't know what the best approach would be for them specifically, but I think most people understand that ARGs are a "you snooze, you lose" situation lol.

I've been thinking about this post over the past few days, and one aspect that could be interesting to explore as a designer is whether you want a Puzzle or an Event.

If you are doing it as a Puzzle I think the trick is balancing how accessible it is (ie. can the average person do this, not just the tech wizards and super fans). For a persistent puzzle I'd lean considerably more accessible than data mining, but that doesn't preclude secret web pages and ciphers and stuff.

If you want an event on the other hand, I say lean into it's temporally limited nature. Look to things like Blaseball and Thomas Dolby's Floating City game. A key part of that engagement is the feeling that this is happening Now and not Later. While it sucks for archival purposes, I'm very keen on the idea of games that aren't going to be around forever. The worst of both worlds imo is trying to capture the lightning in a bottle of community engagement again and again, leading to exhaustion in both your players and your team.