Enemy Awareness, and Stealth Combo breaking.

[Xenthana]

So I've been a long time player of this game, back so far as starmap 1.0, and I've always been fond of doing stealth even back when it wasn't really viable. I've seen the systems behind it change and adjust through several iterations, but while there are several good things I could say about the current state of stealth in Warframe, there are a couple things I'd like to draw attention to that I personally see as either bugs, or unfit for the way the game works.

^{The first, and most annoying issue, is touch-based alerting.
Most notably, when two enemies are standing side-by-side, it becomes nearly impossible to kill both with melee without losing your stealth kill multiplier. This occurs because, regardless of how quickly the strike lands, the last to be hit counts as 'alerted' because the first's corpse is touching them upon death, thus breaking the combo.
This is a very recent issue, as I don't recall ever having this issue prior to the release of PoE [I was on hiatus shortly before it released, until around two weeks ago.]}

^{The second, is that enemies can hear when a melee attack strikes an obstacle near them.
You go to swing at an unalerted enemy from behind, but the tip of your blade strikes a wall, a box, maybe a bit of railing just before hitting the target, and suddenly they become 'alerted' and the multiplier is broken, even though they died within less than a fraction of a second after the noise was made.
This 'feature' existed the last time I played, so clearly it was intentional, however given how melee works in this game, it seems rather unreasonable to say that hitting a wall and the target at nearly the exact same time breaks stealth.}

^{It doesn't make much sense that an enemy can be alerted instantly in such ways and it be counted against the combo. So, I'd like to propose something.
A grace period; a moment of time, even so short as a second, where an enemy which would be alerted by anything short of actually seeing a body or warframe, still counts as unalerted.
Something like this would aid not only melee, but burst fire weapons which suffer low individual shot damage in trade for multiple quick hits that are not counted as a single shot, unlike shotguns.}

The list has grown significantly, so instead, I've summarized and list the problems and suggestions;

Problems
> Stealth Combo Breakers

• The instant death of an enemy's ally beside or behind them instantly puts them on caution, even if the death is 'silent'.
• An enemy touching another will caution the last to die even if both deaths are caused by the same strike.
• When two enemies are touching, and only one dies, it will sometimes not count as a stealth kill, regardless of the weapon used, silenced or not.
• Striking a wall, obstacle, or sometimes even another enemy, instantly causes caution on anyone nearby, even if their death follows within the same instant.
• Spawn immunity to stealth combo, when spawning or when teleporting to 'catch up', has no indicator whatsoever.

> General Stealth Issues

• Enemies on ramparts remain cautious permanently on the minimap, failing to indicate when they return to unaware.
• Enemies closely overlapping on the minimap create significant confusion as to their state of alertness.
• Melee is supposed to be silent, but isn't. Anything hit will be heard for an upwards of 5~10m, especially breaking crates.
• Enemies which are left in a previous tile on something such as Exterminate, will rally to whatever tile you're in if you perform a stealth kill of any kind, despite not being aware.

Suggestions

• Add a fourth state of awareness, perhaps called 'startled', between unalert and cautious, in which certain things do not immediately count against stealth combo. Perhaps in this state, enemies investigate sounds or ally shouts, and only become cautious if they see or recognize something actually alerting, such as getting a good look at an arrow stuck in the wall, or seeing a body or the Tenno themselves.
• Give the arrows on the minimap colors rather than filled states, such as dark green for unalert, yellow for startled, orange for cautious, and red for alerted. This solves enemies being clustered on the map, making them impossible to tell apart.
• Alternatively, make it so that a kill that would ordinarily break the combo multiplier, instead gives normal affinity [as if without the multiplier] without breaking the combo. Or, if a penalty must be made, simply remove one stack of combo rather than the whole thing. Note, that even without a penalty, there is still the risk of the timer running out due to not being refreshed by a kill.

 

Edited March 22, 2018 by Xenthana
Added a summarized list of problems and potential solutions.

[NoSpax]

It's harder to do stealth in a room, the enemies spawned and didn't get out. How am i supposed to stealth kill a group of 8 enemies without Ivara or Equinox? 

I recently had this on Venus (V prime? The extermination node). I walk up to a locker room and there are 5 or more enemies inside. 

[Xenthana]

The work-around, which, is the same solution for my issues, is to kill individual enemies (while cloaked) with direct stealth kills or silenced shots, in an order that causes the least enemies to be alerted right away, then leave, kill other things to keep the combo going, then come back to clean up the group when they've calmed down.

But this is often unreliable - and costly to keep cloak going longer, but also quite tedious, especially when you have a weapon that could one-shot any enemy in range, but doing so breaks the combo because it either hits an obstacle, or an enemy 'feels' their buddy die next to them.

This also applies to projectile weapons such as bows or throwing stars. The flying body can kill another, but if they're right next to eachother, there's a high chance of the combo breaking due to the reason I just described, where they just 'feel' their buddy die and are alerted instantly.

Edited March 15, 2018 by Xenthana

[NoSpax]

I know about stealth, I have played MGS1&2 on PSX/PS2 and Prototype inside bases. Pick a single target, who isn't covered and take him out. Moving targets on patrol first. XD

I noticed that a hit through an obstacle /door doesn't count as stealth and breaks the combo. As if the arrow loses it's stealth attribute when it passes an object. Bad thing is, corpses count sometimes as object, too. 

Either a strange coincidence, sometimes you one-shot 2 enemies at once and get a bonus x2, contrary to the "you hit object and reset counter" 

Actually they hear their companion die, as for whatever reason a person can emit deathcries, when they instantly die. (if they see a dangling corpse violently ragdolling on a wall, everyone would go alert, so no complains here) Wiki says they go into minor alert. But why this state doesn't allow stealth kills is beyond my thinking. They know something is there, but not who or where. Here stealth kills should still work instead. If someone spots you in minor alert, enemies should go into Full Alert.

Warframe could need 4 states of enemy alertness. The first two allow stealth, the latter ones, not. (can we have a Mod to see states of enemies on HUD or at their cone of vision, please?) All enemies start out in state 1 "Calm". Going from state 2 "startled"  to state 3 "aware" should have a small delay, a timer. If an enemy on state 2 notices another enemy die in his field of vision, he will go state 3. If an enemy dies outside of vision but perception,  he will remain in state 2 for X,x seconds (the timer) in confusion (maybe make this Switch Teleport look around thing). If you kill another one he can notice while the timer runs, he goes state 3 or even 4 (when he spots you), being fully alerted. If you don't kill someone in state 2 (so lay low) , and the timer runs out, he will remain in state 2 for some duration before he reverts to 1, being unalerted.

Well, if AI can be broken down to a flowchart, if may be convoluted, but easy to understand. 

TL;DR: I give us a little more time before enemies go full aggressive and have us kill them stealthily anyway, before they can call backup. 

Btw, is opening boxes still Loud, even when Melee is supposed to be Silent? 

Edited March 15, 2018 by NoSpax

[Xenthana]

I agree, four states would be much nicer. Also an indicator for if an enemy is in 'spawn/teleport immunity mode', where it penalizes you for killing them too quick, would be nice, since I've killed many enemies that I thought had already been there and lose my multiplier as a result.

I'm not sure how I feel about being able to see exact cones of vision, but that is one thing to mention; it can be very difficult to see what state someone is in by the minimap alone, when there are a lot of enemies close together. Perhaps if they used colors instead? Such as, gray or some other obscure color for 'immune', dark green for totally unalerted, yellow for startled, orange for aware, red for alerted?
Also a fix to enemies showing as permanently aware while on Ramparts, when you can still get stealth kills if you wait a bit.

And yeah, hitting anything within a ~5m radius of enemies is considered audible, which brings me back to the whole striking a wall on accident while attacking something.

.. Come to think of it I think I'll just add a summary section to the first post as this list is growing a bit..