Bravo - I always love this kind of creative thinking! As you said, there's nothing that necessarily says Visible and Invisible touch encounters need to be mutually exclusive from each other, and if you work hard to design an interesting and interactive Scouting system, you might have something that's far more than the sum of its parts.
With that said, there are some very real frustrations that come with invisible or random encounters (which can be reduced but never fully sifted out via thoughtful design), and I personally think these frustrations shift the scales far into the favor of using Visible Encounters, as a general rule, so long as you can implement them competently. If your game's dynamics (and theme) really can gain a lot by mixing the two types together with a Scouting system, go for it! But I would consider it more of a beautiful exception than a rule of thumb.
Thanks! You're completely true, it will require vastly more work than "set random encounter rate to 13%". And yes, the vast majority of the encounters would still be visible - the idea is that the "invisible" encounters generate additional tension and unpredictability, but that only works if they are an addition to an otherwise predictable system. More below.
This 100%. This is kinda why I mix-and-match features so often, because sometimes they open up new avenues for Cool Gameplay that you wouldn't get on their own.
Like yeah, I'm aware of the faults in every system present here, but it's making the best of them that really matters. That said, the idea
@Anthony Xue presented of invisible enemies you can't see sounds pretty badass: I can totally see myself using that for enemies that try to mask themselves so you can't see them with the naked eye.
I also feel for visual encounters games need to utilize line-of-sight and/or area of detection even if they're not stealth to make them not-annoying. So even if you get squished into tight corridors you can still sneak past them.
Thanks as well. Funny that you mention detection and line-of-sight... it probably matters that my game looks like on the screenshot below.
In general, the system is supposed to go like this - I won't have specific enemies show up on the map, but "encounter markers" in blue, red and invisible. Blue encounters are "dormant" and won't necessarily attack right away (think some bandits gathered around a campfire in their cave hideout). If you get into the event's trigger range, your scout will tell you what you are about to be facing. You will then have a choice of attacking them (surprise round!) or communicating, maybe getting them to leave with a bribe or questioning them and learning that they're not the bad guys at all etc. etc.
Red encounters are on the move, patrols actively looking out for someone they would have to fight. Whether you will get any options once in the event's trigger range will depend on your scout's ability; if it's high enough, the game will treat this as "you spotted them early" and give you more options, otherwise it's just fight or run (and maybe not even that last one).
"Invisible" encounters could either be enemies that are indeed hard to notice (wraiths...) or enemies that are specifically aware that you are coming, can be expected to react skillfully to a hostile intrusion and have thus been laying an ambush (ex.: the Doomguard in their own fortress, especially after you've been breaking doors and smashing chests all the time). Then it's an arms race between your scout's scouting ability and their ambush ability whether they will be revealed to you (not 100% sure how to do this technically - I could either have a parallel event that continuously makes scouting checks and thus sets other event pages active, or simply one check at the beginning of the level, although that could not account for equipping/unequipping scouting-enhancing items). All of this of course is somewhat more "believable" in a 3D environment, where danger can literally lurk unseen behind the next corner, than in a top-down view.
The system of generic encounter marks/scouting reports also lets me use vastly different troops for encounters without having to think about "correct" representation. You were able to catch the Doomguard Captain in his quarters? Then he won't be present in the fight in the throne room.
Obviously, all of this needs a lot of work to implement, and as a result, a random bandit cave will only have a handful of encounters instead of like 20. There also is the danger of the whole system being rather taxing on the player - "just slay whatever moves" is a somewhat primitive premise, but it also keeps things flowing. But I guess that's something that can only be found out through playtesting...