Stealth multipath in small places

Today I'll give you some tips to build multiple paths and rich gameplay in small areas.
Typically, a small place would be corridor of 8m x 8m x 30m which, by video game standards is a really small gameplay space.

Basically it comes down to two things : Verticality and Visual occlusions.
It's mostly about breaking down space into multiple logical gameplay paths and it's a technic I developed and used successfully more than 10 years ago to build Splinter Cell multiplayer levels :)

VERTICALITY
Stop thinking about ground floor only and create paths at various heights.
Layered paths at various heights have the advantage of being easy to read by the player + it usually feels normal that NPC don't see you when you aren't on the same layer.

Note : you might want to break the "Stealth" paths into pieces to force the player into dangerous territories.

OCCLUSIONS
A simple panel, a curtain or a big pipe can create a good occluder creating new paths and places to hide in your layout.
One of the benefits of visual occluder is they are less dependent on light and shadow, and they tend naturally create nice and inviting dark places if you place your lights correctly :)


TYPICAL PROCESS
A - General Layout
Block out the logical flow and layout so your volumes and general connectivity make sense.
In our example, will take the example of a large corridor (Military base?, Warehouse?, Factory?).

B - Add vertical layering
Think of what your place is and how you could add more paths at various heights.
In our case, it will be mid height walkway and a large ceiling pipe.

As  you can see, instead of one single way, we now have 3 potential paths to reach the exit door : ground, walkway, and the pipe under ceiling.

C - Add occluders
In this next step, I've carved some space the area under the walkway and added occluders (crates, car, curtain, etc)
This way, I created an extra path without even eating any space and the area now offers much more potential than the traditional and empty corridor we started with while still having the same footprint.

Note that one benefit of this method is that you naturally build places with inter connected paths that are all sharing the same action space.

C - Balancing Paths
At this point the upper path on the pipe, and the one under the walkway behind the crate would be super safe, so you'll probably want to "cut" those path to force the player out into the dangerous areas.

This can easily be achieved by simply cut the continuous stealth paths and to refine the balancing, you'll want to identify the dangerous areas (typically, the drop at the end of the upper path) and add a few extra occluders / hiding place for emergency situation.

CONCLUSION
Try to think in terms of paths and layers of navigation.
Not only will you get the most out of otherwise boring areas, but it will help you structure your work (connectivity, flow, paths) and have an easiest time balancing your level. (adding/removing access, cutting/adding connections and paths)

Of course, no stealth layout would be complete without an emergency escape path for the player, but this will be for another topic ;)