Sneak

The higher your Sneak skill, the easier it is to remain undetected, steal an item, or pick someone’s pocket.

Successfully attacking while undetected grants an automatic critical hit.

Sneak allows you to pick your fights and, with high Perception, position yourself for easier survival in firefights.

Picking off enemies like a Super Mutant with a Missile Launcher before they can attack makes survival easier.

Avoiding groups like Talon Company Mercenaries is also a benefit of Sneak.

Stealing is a good way to acquire better guns early on or items to sell.

Critical hits are devastating in Fallout 3; a critical sneak attack headshot can be extremely effective, especially with a Combat Shotgun.

The Better Criticals perk enhances sneak attacks.

Sneaking away from every enemy will not grant experience and is only helpful in combat if you can also fight effectively.

Sneak is an all-or-nothing skill; it's hard to sneak near enemies with a sneak skill below 70.

For avoiding fights in open terrain, around 50 Sneak is sufficient.

For combat purposes, aim for a higher Sneak skill.

Remember to turn off your Pip-Boy light when attempting to sneak.

With a Sneak score of 100, the Silent Running Perk, and Chinese Stealth Armor, your character will become virtually undetectable, even when attacking with a Melee Weapon or Unarmed, provided you avoid running into foes.