Sneak (Fallout: New Vegas)

For a cross-game overview of this skill, see Sneak.

Skill
Sneak
Fallout: New Vegas
Modifies	Chance of being detected while sneaking and pickpocketing Allows a wider range of Holdout weapons
Affected by	Agility
Base value	2 + (2 x Agility) + ceil (Luck / 2)
Related perks	Broad Daylight, Friend of the Night, The Professional, Mister Sandman, Silent Running, Ninja

“Quiet movement, and the ability to remain unnoticed. If successful, you will be much harder to locate. You cannot run and sneak at the same time.”— In-game description

Sneak is a skill in Fallout: New Vegas. It determines the chance of being detected while sneaking.

Initial level

$\text{Initial level}=2+(2\times\text{Agility})+\left\lceil\frac{\text{Luck}}{2}\right\rceil$

Example: A starting Agility of 5 and Luck of 5.

$2+(2\times5)+\left\lceil\frac{5}{2}\right\rceil=15$

Description

Most aspects of the Sneak skill are the same as for Fallout 3 Sneak. This includes the initial statistic, the sneak meter, stealing and pickpocketing, and Sneak Attack Criticals. However, unlike in Fallout 3, sneak is determined by the character levels of the actor sneaking as well as the actor attempting to detect them.

Further, the detection while sneaking is modified by other factors such as the class of the armor worn as well as its weight (medium and heavy armors like Power Armor make more noise, and light armors make none), the light levels of an area such as day or night, if the Pip-Boy light is on or off, how fast one is moving, being in an interior or an exterior location and the noise level of weapons used with silent weapons being undetectable.

Sneak states

The sneaking state is displayed while crouching and alerts the player character to detection and possible detection.

• [HIDDEN] means being undetected. In this state, attacking a target guarantees the sneak attack critical bonus, pickpocketing is available, and it is safe to steal, lockpick, or otherwise access "owned" property.
• [DETECTED] means being in sight by one or more targets. Pickpocketing is enabled, but almost always fails. Attempting to steal, lockpick, or otherwise access "owned" property will fail, and may result in friendlies turning hostile or confiscating stolen goods. Sometimes an unfriendly target will see it and this will be shown instead of [CAUTION] because they haven't identified one as hostile or a target.
• [CAUTION] means one or more unfriendly targets are suspicious of presence and are searching for the character. After a time the enemy will dismiss the disruption and the state will return to [HIDDEN]. Pickpocketing is disabled for the enemy searching for the player character. Attacking in this state will not cause a sneak-critical hit.
• [DANGER] means hostile NPCs are aware of one's presence, but they do not know the current location. They will actively search at or around their last known location. If [DANGER] is flashing, it means that the enemy has the player character in sight and will engage them. The state can be returned to [HIDDEN] by moving away and staying out of sight for an extended period of time. As soon as the conditions are satisfied for any state, it replaces the one above it on the HUD even though one may still be in the [HIDDEN] state to several targets around them. Essentially, it reports the worst detection state towards the player character of all potential targets. Once all targets that satisfy the most-elevated state are dead (as in killing everyone actively pursuing the target in [DANGER]), the state will revert to the highest remaining state amongst the remaining targets.

Factors in successful sneaking

• Sneak skill: The sneak skill applies whenever the player character crouches. The higher the Sneak skill, the easier it is to remain undetected while attacking, stealing, or picking someone's pocket.
• Cloaking fields: The Stealth Boy will wrap the user in a cloaking field that makes them more difficult to detect while sneaking, rendering the character virtually undetectable by visual sighting. It should be noted that this field only increases one's sneaking ability, and the field will be negated if leaving sneak mode in any conventional manner, such as firing a loud gun, since the cloaking field does not mask sound-based detection.
• Enemy's Perception: Enemies with low Perception are easier to sneak around than enemies with high Perception. A target's Perception will be impaired (a -4 reduction) if they have a crippled head.
• Line of sight: While out of sight an enemy can only detect the target through sound.
• Light level: The target is more difficult to see in dark areas or at night if outdoors. If the Pip-Boy light is active, it will give away the position.
• Distance: The farther away the target is from the seeker(s) the less likely they would be detected.
• Movement: The player character is hardest to detect when motionless and easiest to detect when running. One can avoid the sound aspect of this by the perk Silent Running. Moving faster while within line of sight will still make it easier to be seen, but one will no longer get any penalty for movement speed to sound made. Note that looking around counts as movement, but not as much as movement over ground. If standing in shadows with a direct line of sight to a target not aware of the location, looking around may very well make the target investigate, or immediately end with being found.
• Contact: Touching or running into targets while crouched will immediately alert them of position. Regardless of how hidden one is, bumping into a target, friendly or otherwise, will immediately result in detection. This also applies to robots that have been deactivated using the Robotics Expert perk.
• Equipped weight: The total weight of all equipped items (weapons count only if they are in one's hands) makes footstep volume louder for non-player characters. Silent Running removes this penalty entirely, allowing full sneaking ability in any equipment. The footsteps are still audible while sneaking with the perk, but non-player characters will not hear it.
• Sound: Most guns make noise. Louder guns make one easier to detect. A full overview of weapons based on their sound level can be found here. The Pip-Boy's radio has no effect on sneaking.
• Dead bodies: When an enemy spots a dead body, it will often enter the [CAUTION] state and move toward the dead body. This can often create a more or less perpetual [CAUTION] state while one remains in the area. If a dead enemy can be grabbed and dragged out of the way before it is found, the player character can retain their hidden state.

Sneak attacking

Main article: Sneak Attack Critical

A Sneak Attack Critical occurs in Fallout 3, Fallout: New Vegas, Fallout 4, and Fallout 76 when attacking while [HIDDEN]. Successfully hitting the target will result in a guaranteed critical strike (unless the weapon does not allow critical hits), while doubling (ranged) or quintupling (melee/unarmed) total damage.

Pickpocketing

While sneaking and [HIDDEN], using the "activate" function while facing a non-player character (when in touching range) will allow pickpocketing them; in other words, stealing items that are in their inventory. This will open the inventories of both the player character and the target. Items can be transferred either way, and thus items can also be planted on them (also known as reverse-pickpocketing, or the "Shady Sands Shuffle").

For each item the player character steals or plants in a non-player character's inventory, there is a chance of being detected by the target NPC. The formula for a successful pickpocketing attempt is as follows:

$\lfloor 40+(0.6\times {\text{Player Sneak}})-\left\lceil {\frac {\text{Item Value}}{2}}\right\rceil -(0.6\times {\text{Target NPC Sneak}})\rfloor ={\text{Success Chance}}$

Verbally, this means chance of pickpocketing success increases with the player's Sneak skill level and decreases with the target's Sneak skill level as well as half the value of the item stolen (rounded up to the nearest integer). The overall success chance will be rounded down to the nearest integer. Item value here is not the item's base value, but rather its value dependent on the condition (HP) of the item (see that page for the value formula). Since item value affects the overall chance of pickpocketing, this can lead to unusual situations where, for example, a suit of power armor in nearly-broken condition may have a higher chance of being taken than a well-maintained 9mm pistol. Additionally, the maximum and minimum chance of a successful pickpocket attempt is capped at 85% and 5%, respectively. This means any item with a value of 190 caps or more will only have a 5% chance of success, even with 100 Sneak skill or with using a Stealth Boy.

If detected, the non-player character will automatically reclaim the item(s) taken and the player character will not be able to pickpocket that non-player character again (at least not straight away - leaving the area and returning 24 hours later should allow the player character to re-attempt this).

The player character cannot steal items an NPC currently has equipped. To steal an item the non-player character is wearing or using (armor or weapon), the player character can reverse-pickpocket a better item (higher DR for armor, higher damage value for weapons) into their inventory and then leave and re-enter the area. The non-player character will equip the item with the highest stats and then the player character may try to steal the item they were using before. For melee weapons, reverse-pickpocket a better ranged weapon onto the non-player character along with the appropriate ammunition. When the non-player character is reloaded, it will instead equip that new weapon. Steal the melee weapon and the ammunition they were given, and reload the non-player character. The non-player character will be unarmed and the player character can steal the ranged weapon back. Keep in mind that just because the player character can do more damage with a specific ranged weapon doesn't mean that the non-player character will (usually but not always). Experiment to get the desired effect.

Successfully stealing the ammunition from an non-player character with a gun equipped will immediately render that non-player character unable to fire their gun. The amount of ammunition an non-player character is carrying will not match the amount they could fire if not pickpocketed (which is actually unlimited as long as they have 1 round for that weapon); this discrepancy can be attributed to gameplay purposes. This tactic can be used to influence the outcome of both non-player character/PC and non-player character/Non-player character conflicts. Concerning non-player character/Non-player character conflicts, this allows remaining non-hostile to non-player characters on both sides of a conflict (by not needing to intervene with gunfire) while still ensuring victory for one side or another. Mind that after some time, possibly the general respawn period of 72h game time, ammunition will be restored on NPCs.

Non-player characters will notice when other NPCs are pickpocketed, hence the [DETECTED] sneak state, but in large open areas one can maneuver into gaps or around corners to avoid line-of-sight and return to [HIDDEN]. Non-player characters lying in beds may appear to have their back in one's direction, but still have one in sight. This is because as far as the game is concerned, the direction the NPC is facing while lying down is only an animation and is not their actual line of sight. To get "behind" an non-player character lying in bed, go to the foot or head of the bed.

The player character can also use pickpocketing offensively to plant a live explosive. This will detonate after a short time, automatically killing the target regardless of the PC's Explosives skill or the target's health or resistances.

Sneak-based perks

Perk	Requirement	Level	Additional Requirements
Friend of the Night	30	2	Perception 6
The Professional	70	6	—
Mister Sandman	60	10	—
Silent Running	50	12	Agility 6
Ninja	80	20	Melee Weapons 80

Interactions that require Sneak skill

• 25 Sneak to convince Trudy to help set up an ambush for the Powder Gangers during Ghost Town Gunfight.
• 40 Sneak to discreetly pull the pin off Private Crenshaw's grenade, leading to his death during I Put a Spell on You while helping Caesar's Legion.
• 45 Sneak to point out to Klein that the Stealth suit Mk II's dampening field can successfully slip through the protective field and get into Mobius's Forbidden Zone.
• 50 Sneak to successfully carry improved holdout weapons into restricted areas such as casinos on The Strip and the interrogation room at Camp McCarran.
• 50 Sneak to persuade Mister Holdout to sell improved holdout weapons.
• 60 Sneak to successfully reach Ranger Ghost at the Mojave Outpost without her realizing, causing a unique dialogue.
• 75 Sneak to taunt Father Elijah about hiding out in the Sierra Madre vault and getting him to personally intervene during Heist of the Centuries.

Ways to improve Sneak

Permanent

• Leveling up (up to 10 + INT/2 + 2 with Educated perk)
• Chinese Army: Special Ops Training Manual (+3 or +4 with Comprehension perk)
• Agility Implant (+1 depending on current Agility, a perfect Agility of 10 will see no benefit)
• Tag! (+15)
• Skilled (+5)

Temporary

• Assassin suit (+10)
• Blood-Nap (+10)
• Broad Daylight (+15 when Pip-Boy 3000 light is on)^(Note)
• Chinese stealth armor (+5)
• Dead Horses stalker armor (+5)
• Fire ant nectar (+2-8 depending on current Agility, a perfect Agility of 10 will see no benefit.)
• ¡La Fantoma! (+10 or +20 with Comprehension perk)
• Recon armor (+5)
• Stealth Boy (+100, +75 cloaking field)
• Salt-Upon-Wounds' helmet (+5)
• Stealth suit Mk II (+15 or +25 with the Firmware 1.1 Upgrade)

^ ^(Note) Broad Daylight does not offer a significant boost to sneak to offset the penalty for having the Pip-Boy's light on.

Notes

If an item is in a difficult spot to steal but is not in an inventory of some kind (wardrobe, desk, person, etc.), one can easily steal it by the Grab function and taking it somewhere out of sight. NPCs do not perceive grabbing as stealing so they will not react unless when stealing the item the player character is still in their sight.

Bugs

PC Playstation 3 Xbox 360 Sneaking at lower character levels can cause higher level enemies to detect you further away than if you weren't crouching at all. ^[verified]

References

Non-game

Skills Fallout Small Guns · Big Guns · Energy Weapons · Unarmed · Melee Weapons · Throwing · First Aid · Doctor · Sneak · Lockpick · Steal · Traps · Science · Repair · Speech · Barter · Gambling · Outdoorsman Fallout 2 Small Guns · Big Guns · Energy Weapons · Unarmed · Melee Weapons · Throwing · First Aid · Doctor · Sneak · Lockpick · Steal · Traps · Science · Repair · Speech · Barter · Gambling · Outdoorsman Fallout 3 Small Guns · Big Guns · Energy Weapons · Unarmed · Melee Weapons · Throwing · Explosives · Medicine · Sneak · Lockpick · Science · Repair · Speech · Barter Fallout: New Vegas Guns · Energy Weapons · Unarmed · Melee Weapons · Explosives · Medicine · Sneak · Lockpick · Science · Repair · Speech · Barter · Survival Fallout: The Roleplaying Game Small Guns · Big Guns · Energy Weapons · Unarmed · Melee Weapons · Throwing · Explosives · Athletics · Medicine · Sneak · Lockpick · Pilot · Science · Repair · Speech · Barter · Survival Fallout Tactics Small Guns · Big Guns · Energy Weapons · Unarmed · Melee Weapons · Throwing · First Aid · Doctor · Sneak · Lockpick · Steal · Traps · Science · Repair · Pilot · Barter · Gambling · Outdoorsman · Speech