Stealth

Stealth is often overlooked in Cataclysm. While most players are familiar with night raiding, many believe that there is no such thing as stealth because the game lacks a distinct "stealth mode".

In truth, the game has one of the more dynamic and interesting stealth systems going. Rather than giving the player a hidden or detected state, each enemy has its own senses and AI and will behave in generally predictable ways according to their goals and capabilities.

For this guide, I'll be talking about the most relevant threats, hostile monsters. Mostly this means bugs, zombies, and robots. Most of this stuff is more broadly applicable and applies to NPCs as well. Non-hostile "monsters", like deer, mostly use the same triggers for provocation, but in their case they generally just run away. Note that aggression is not the same thing as detection!

Detection

Enemies typically exist in a neutral state. They may patrol around, and if something gets in their way they may get frustrated and smash it, but usually they're pretty calm.

Detection States

Enemies have multiple detection states, each one triggers a behavior which overrides the former state. Roughly, these are:

- Smells the player - Heard a provocative noise - Saw a target

If an enemy smells the player, it will follow the scent.

If an enemy hears a provocative noise, such as the sound of a window breaking, someone shouting, or a gun going off, it will become alerted and move aggressively toward that sound. This aggressive movement will include things like bashing down doors and giving warning calls. These are themselves usually provocative noises, and will trigger other enemies that hear them.

If an enemy sees a target, it will drop whatever it was doing to get to that location and do whatever violence it is capable of.

Scent

The player (and only the player, due to computational limitations) emits an invisible scent cloud to about eight tiles. This scent cloud is blocked by smoke, walls, and doors, but not by most windows, unless they're taped up. The scent cloud lingers for several seconds, and can be pushed around by the wind. The scent cloud is strongest at the middle and weakest at the edges.

Basic zombies and all robots cannot detect the player by scent. They just don't have the anatomy for it.

Most land animals, zombie animals, and some evolved zombies, such as the zombie predator, can smell you. If they catch your scent and they aren't distracted by something more pressing, such as a wasp stinging them to death, they will try to find you. They do this by stepping to the nearest available tile which has a higher scent strength than the one they're in. If no such tile exists, they'll randomly pick the next strongest tile. If there are no more adjacent scent tiles, they will go back to just wandering around.

The weak scent trait reduces the size of your scent cloud, but not by much. You can get the same effect from the Olfactory Mask CBM. I'm not sure if they stack. You should probably assume they don't, unless you know better and are editing this wiki. Similarly, strong scent and smelly increase your scent cloud. Certain traits, like Rosebuds and Mammal Pheromones affect the nature of your scent and may change how some enemies react to you, but generally speaking they will not throw zombies off your trail.

Sound

As long as you aren't deaf or wearing earplugs, you can see how much sound your actions make by looking at the "Sound:" line on your sidebar. Generally, a step will make about 8 sound, meaning it can be heard up to 8 tiles away. Melee attacks, bashing furniture or doors, opening/closing doors, breaking windows, and firing bows or guns will all make sounds at your location. Gunshots are generally extremely loud, and even with suppressors you should generally expect company if you fire one in a city. The exception would be very low calibers like .22. A suppressed .22 can actually be whisper-quiet, making the otherwise unimpressive cartridge an attractive choice for stealth users.

Some enemies can hear better than others. These include very strong enemies such as the Headless Horror, so always consider your situation carefully before doing something noisy.

Enemies won't always react to sounds if they hear them. Zombies won't, for instance, cluster up in one spot because one of them made a footstep noise. Generally, more destructive, louder, or obvious (IE speech) sounds tend to provoke enemies much more than basic environmental sounds. Enemies who hear provocative sounds will generally do whatever they can to get to them, often making a lot of noise (by screaming, smashing furniture, breaking windows, etc) and thereby alerting their friends in the process.

Ants and Slimes

Ants and slimes deserve special mention here. Slimes are entirely blind, and ants have a very limited visual radius. Both enemies hunt by sound. Which leads us to...

Sound as a distraction

As long as enemies cannnot see you or another monster they hate, they will generally prioritize investigating sounds. This means you can use sound to lure enemies to a location. The most obvious way to do this is by shouting, which can be accomplished by pressing C. This will make a loud sound (increased by your strength and some mutations, decreased by mouth encumbrance) which will draw enemies to the spot you were standing in when they heard the sound. But that's not the only thing you can do.

Glass items will shatter and make a decent amount of noise when thrown. You can, for example, throw a bottle at a wall and lure enemies toward that spot. Similarly, throwing a rock through a window will break it and make enemies assume something is going on over there.

Several devices, including smartphones, laptops, e-ink tablet PCs, noisemakers, and talking dolls can play music or sound on their own. Such an item left on the ground will often draw enemies toward it, clumping them up for easy disposal via a grenade, trap, or a sniper. Conversely, you could just sneak around them while they're distracted.

Crouching

Crouching greatly slows your move speed (less so if you're a quadruped, but also makes your steps quieter.

Ninjutsu

The martial art Ninjutsu causes your steps and melee attacks to be silent. The benefits of this should be obvious.

Mutations and Traits

Cephalopod's leg tentacle mutation makes their movement completely silent. The Light Step trait also reduces movement sounds, as does gastropod foot.

Sight

The main tool most enemies use for detection is sight. If an enemy can see you at all, it will instantly identify you and go hostile. Unless you have the inattentive trait, you can press x to look at enemies to see if they can see you. Many tilesets also print a red exclamation mark next to their icon in this case.

Darkness

Enemy vision is all or nothing. Enemies have two vision stats, day, and night. If a tile is Bright or lighter, they use their Day stat. If it's not, they use their Night. For the most part, zombies can only see about three or four tiles in any direction when it's dark, even on moonlit nights where most players can see much farther. In these situations, they will rely on sound and sometimes scent to track the player down. Given that most zombies don't have working noses and there are so many ways to be silent or confuse their sense of hearing, this gives the player an enormous advantage over them.

Some enemies see just fine in the dark, or even have better night vision than day. Wouldn't be the cataclysm if there wasn't a wrench in the works there, would it?

Line of Sight

Enemies have very short memories, and pretty much no ability to predict what you'll do. If an enemy sees you, don't give up hope. All you have to do is break line of sight. Closing a door, stepping behind a wall or a tree, or turning off your flashlight will usually do the trick.

Once line of sight is broken, enemies will remember where they last saw you, and for the next several seconds, their priority will be to get there unless something distracts them. Generally, the safest thing to do is to be somewhere else when they do. If an enemy still doesn't have line of sight to you by the time they get to the point where they last saw you, they'll quickly give up and find something else to do.

Crouching

Some furniture, such as countertops, will actually block line of sight if you crouch directly behind it. This is invaluable for sneaking around enemies like robots, who can often very quickly shoot you dead if they spot you. In some cases (such as with large cardboard boxes), it's actually possible to grab this furniture with G and crouch-walk around with a line-of-sight blocking item in front of you.

Hiding Places

Large cardboard boxes, when placed as furniture, can conceal characters and monsters who step inside them. This is also true of dumpsters and a few other items. This makes the character totally invisible to everyone who is not directly adjacent to the box. Obviously this isn't foolproof, and if an enemy saw or heard you go into the box, it will quickly find you, but there are times when this will be a lifesaver.

Some enemies, such as roaches, can hide in places that a survivor wouldn't fit, and will only reveal themselves when you get close. Be careful when exploring cluttered basements!

Mutations, CBMs, and Gear

Cephalopod's camouflage skin mutation passively reduces the range at which they can be seen by most enemies. The cloaking system CBM and FB51 Optical Cloak (sometimes available at the Hub 01 shop) can temporarily grant near-total invisibility, but have a high power cost. The hologram cloak creates a holographic decoy of the user which will throw enemies off the trail.

Also, turn off your damn flashlight!