Yeah, I’m a big FromSoft fan too and totally get where you’re coming from. I think one thing people forget is that Souls games do kinda have a built-in difficulty slider: grinding. If you’re stuck, you can farm a bit, level up, upgrade gear, and push through. It’s not a setting, but it works without breaking the game.
I would say it's more than a "difficulty slider" -- it's the core, blood, and soul of the game (puns intended). It throws something that may initially seem impossible at the player, then says, "Figure out the pattern." Grinding and leveling stats and gear will allow you to make a couple of additional mistakes, perhaps, probably shorten the fight time, but the player will simply face an even stiffer challenge around the corner from that point and be right back at square one.
I think the magic of that approach is that the player learns to just relax, get a feel for their build, and systematically repeat a challenge as many times as needed until they figure out the trick. The whole game is the idea of doing the same thing over and over again until what was once next-to-impossible becomes offhandedly easy. Gear and level and attributes don't really affect that central system all that much...
...at least, when players actually figure things out on their own instead of looking up builds, tutorials, and walkthroughs online...
...and
that is the reason that I think Dark Souls started having more mass appeal. With all of the "how-to" stuff available, many gamers that would have played 2 hours of Dark Souls and put it down forever instead just made the game easier for themselves by removing the actual challenge and just following step-by-step instructions. At least, until they got a feel for the game, and
then they started to enjoy it more.
The online trove of specific builds, locations of powerful items, maps showing secrets, videos showing the correct timing for bosses, etc. -- not to mention mods that will make things easier -- took FromSoft games from niche titles to the mass market by around the time of Dark Souls 2. I don't think it would have happened if
options had not existed to make the game
easier. Or more difficult, for the people out there who just can't get enough punishment in their games.
If Witcher 4 sticks to one difficulty, I think it needs something like that, some way to power up through effort if you’re having a hard time. Not necessarily grinding XP, but maybe mutagens, potion upgrades, or optional contracts with good rewards.
For this part, while certainly possible, I don't think that would be in-line with the vision of The Witcher games. None of the games have ever included a "grinding" mechanic, and quite the opposite, have specifically tried to avoid anything like that. Take TW3, for example, which simply stops awarding meaningful experience after the player reaches a certain level at that stage in the main quest. Enemies begin providing 1 Exp. Board contracts may provide nothing, but you can still be paid. In order to continue leveling, you need to advance to the next stage of the game.
Cyberpunk still follows a similar system, made even more gradually uphill when the level scaling was introduced. Love it or hate it, it ensures that no matter how far a player character "levels up", they will face a challenge. (Arguably, there are some aspects to that which I think come across as a bit wonky in practice, like doorlocks suddenly becoming
harder because your character got
better at lockpicking. But I'd say the whole point is to specifically avoid grinding in the game.)
The why of it is due to the game's wanting to present a narrative, continuously progressing experience. A contiguous story with a beginning, middle, and end. Around that is wrapped all of these RPG and action mechanics. As opposed to games that create RPG and action mechanics then wrap the
story around
that, like Diablo, Dark Souls, MMOs, etc.
Therefore, rather than making a brutally hard game and giving the players options to "grind" to make it easier, I would foresee CDPR remaining true to its roots and simply keeping the difficulty sliders. If someone wants to just mash the light attack button for every fight, they can. If they want even a chance encounter with a couple of bandits to be a life or death struggle, they can. And either way, the
story will progress smoothly.
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Or...maybe...they could find a way to do both. Who knows? Perhaps they could do something like:
Ciri kneels in front of the fire to meditate. While doing so, the player is allowed to relive old contracts or something like that, but they'll now face different versions of the scenario, additional enemies, tougher versions of a certain monster. All excused away by Ciri
meditating on the combat and exploring the experience with what-if scenarios. She gets to keep the experience, maybe unlock an ability, by meditating. Perhaps she also sees something in her mind's eye she consciously missed about the battlefield. Return to the site, and suddenly there's a hidden chest or unique item stashed in a secret spot.
It could be there if players wanted it, or you could just meditate to heal and pass the time.