Stealth

From Lotro-Wiki.com

Stealth is an ability which allows a character to "sneak" around unseen. Mobs can still sense your presence, especially if you move in front of them. Movement speed is reduced but time can be saved by avoiding fights. Stealth level can be improved by the use of certain stealth items (currently pocket items and cloaks).

Stealthing is a hallmark ability of the Burglar and the Monster Player Warg Stalker.
Burglars gain the ability Sneak at level 4. Movement speed is 50% of normal. Burglars can also take a fellow into Stealth if they stay close by use of Share the Fun; movement speed becomes 30%. These speeds are increased to 70% and 50% respectively if the Burglar has Leaf Walker slotted. The skills have a 10 second cooldown which is shared by Mischief. Burglars can also suddenly hide from view in combat using Hide in Plain Sight (HiPS) which makes them undetectable for 10 seconds.

Hunters can go into stealth mode via Camouflage, but they cannot move around stealthed.

Hobbits and Elves have a slottable racial ability to Stealth; these abilities have a movement speed of 50% and cooldown of an hour.

Lore-masters acquire a Lynx pet that automatically uses stealth; and some mobs (eg Lynx, Wargs and Hill-men) may also initially be stealthed when encountered.

Session Play rangers can move unseen via Ranger stealth. Their most devastating attack, True Shot (Ranger) can only be used when in stealth mode.