Fallout 4 Stealth

The Detection Meter and Sneak Mechanics

Sneaking is a handy ability in Fallout 4, whether you're playing a Sniper, short-ranged character, or getting up close in Melee. In all of these circumstances, you are able to move closer to your effective range before the enemy detects you. What causes them to detect you and the way the meter works seems to be a point of interest for new players, so I'll explain how some of this works to help you be a bit more successful.

The Purpose of Sneaking
When you're crouched, you'll see 'Hidden'. This means you're sneaking. You can use this to pickpocket enemies when behind them, steal items lying around without anyone noticing (just don't make noise!). You may want to avoid battles, or pick off enemies one by one from a distance and be a sneaky sniper. The game's AI will never catch you, though this method can take some time and it's not as useful when you're inside a building.

Sneak Attacks
Sneak attacks deal double damage to enemies, but only if they haven't detected you. You're guaranteed to do double damage if you hit when the Stealth indicator is still green. I have seen a sneak attack occur at red, and now theorize that it has to be on its way back to hidden in order for the sneak attack to work at that point, or else that one opponent has called off their search. Your results may vary, and my memory may be tained. 100s of hours of play, ya know?

Sneak Attacks aren't just for gun users - Players who build up a high level of sneak skill and use melee weapons can do incredible things with the Blitz Perk in the Agility tree - it lets them engage at great distances - between that of a sniper rifle and handgun, while the Ninja Perk will increase the Sneak Attack damage for both guns and melee users - heavily favoring Melee because of how hard it's supposed to be to sneak up close with a super-sledge. Not at all, with Blitz!

While Sneak Attacks won't multiply with your Critical Hit Multiplier, Crits can be used to ensure that a sneak attack will land and make the damage reliable when you need it to be and have a poor chance to hit.

The Detection Meter Explained: Getting Detected

This is best done graphically, so you can understand how the detection indicator works. The meter - indicated by brackets - grows outward, then collapses inward as you near detection:

It goes in reverse as you flee, then initiate sneak again. If you kill all enemies it can go straight back to hidden:

What Non-Perk Factors Affect Stealth Detection?

Daylight, Spotlights and Room Light. Light! - Even the best sneak builds will have trouble in daylight or spotlights - there is a reason for those annoying spotlights in some areas, and lights pointed straight down tunnels that are unavoidable. Many of these, you can't shoot out although sometimes you can use a terminal to disable them. In general, the darker an area the better your stealth will work. Some Armor modifications greatly impact the ability to stay stealthy in dark areas. Note that your Pip-boy's light is far from a spotlight in terms of brightness, but it DOES affect stealth - so shut it off!

Armor Weight - This is a big factor, but only for when you are moving. It matters even with the lightest gear, though you can minimize the impact by moving slowly (Caps Lock on PC) (whatever moves you slow on console!). Using Ultra-light build mods on your armor will reduce total armor weight, while also giving you extra AP. Choose between this and sneaking better in darkness. I like the AP.

Noise - Like above, gunshots without silencers/suppressors will make a lot of noise, and alert others to your presence. If playing a sniper, try to shoot the nearest enemy, so that when their friends come looking they are outside range to fully detect you. Guards will only look so far before they decide it's just the Jet giving them jitters.

Line of Sight - Coming up from behind is good, though some guards patrol. Watching their patrol routes can help you to sneak past them.

Dead Bodies - These seem to put human opponents on edge a bit when they discover them - they'll remark that they have trouble, and it feels like it's easier to get detected afterward. Just my experience, may not be true - could just be dialog.

Perception - The Culminating Factor - All of these contribute based on the Perception of the enemy you're sneaking up on. They may have better hearing and vision, or even sense of smell as with the Wasteland's wildlife. Certain foes have horrible perception, like Ghouls. Others, like Deathclaws - and even worse - Yao Guai, have very high perception. Human opponents that you encounter when your level rises - the harder ones - will have higher perception than a basic raider. Their senses are generally not as in tune as that of beasts, but they tend to be more intelligent and patrol.

Boosting Stealth

There are three main ways to boost your ability to Sneak. First - Agility. Higher agililty directly affects the sneaking ability of your character. They're more light-footed and the higher this stat, the more they'll get out of other boosts.

Second, Perks and Covert Ops Magazines - Namely the Sneak Perk, which gives you +20%, 30%, 40%, and 50% reduced chance of detection the further you take it. In combination with light armor, this can make a massive difference. At the fourth rank, you do not need to move slowly - note the distinction between running and sprinting which drains AP. You do not need to tip-toe with Rank 4 of Sneak. At Rank 5, you can engage Stealth and find that enemies quickly go faster to 'Caution' and the bar expands to 'Hidden' faster.

Covert Ops Magazines give you a reduced chance for each you find, and there are 10 to be found strewn throughout the Commonwealth, often in military-style installations.

There is a Sneak Bobblehead near the end of Dunwich Borers (northeastern Commonwealth), which will give you +10% harder to detect.

Add all these up, and you get over 100% - so you're less than half as likely to be detected by enemies.

Stealth Boys
These eliminate light as a factor for detection and can help you do things you couldn't otherwise, however they do not eliminate sound. Don't waste one and run with it or else enemies will just fire in your general location. Stealth Boys are somewhat rare, expensive, and should be used in situations where you need an advantage - like getting close enough to nail a Deathclaw with a critical sneak attack in the belly, or pickpocketing a fusion core from someone in power armor.

In Closing

At any time, you can run away and engage stealth and enemies are likely to lose you. They don't go chasing you too far, and you can hit them again after you recooperate - or reload. Companion detection doesn't necessarily mean YOU'RE detected, so use that to your advantage while enemies' line of sight is on the companion. Sometimes a companion can draw enemies to them and bring them within range of your weapons, while others flock in to be killed one by one. There are many uses to sneaking in Fallout 4, and I hope this guide has helped you to be just a little quieter and deadlier.