The Hide skill is used once the Sneak feat is activated.
Update 19 revised the mechanism in how a player's Hide operates against an enemy.
A hidden character can be detected with a successful Spot check, depending on the distance from an enemy and whether the character is standing within the enemy's line of sight. Enemies are continually vigilant. When a player is close, Spot symbols above their head (a "+" symbol with one, two or four eyes, in white, orange and yellow colors in order of critical detection) begin to flash above the enemy's head as it tries to hone in on the player.
The symbols and their changes represent the enemy's Spot bonuses, which grow as long as the player is within the enemy's visual arc. Hide works as a buffer against immediate fail of a Spot check. Hide, however, cannot ultimately stop a Spot attempt to succeed but only to slow it from succeeding.
Players may see one to three eye symbols over their head. With Update 19, these eyes are a warning to the player that an enemy is attempting to Spot them. The greater the number of eyes, the more likelihood that the player will be soon detected. A stealthed player that sees any eyes about their character should find better cover immediately.
A discovered player will see a large red eye symbol above an enemy's head.
It is now possible to escape from an enemy's sight by first putting sufficient distance from an enemy (reducing their ability to hear you), breaking the line-of-sight between the player and the enemy, and then returning to stealth. An enemy will search for you for a time and then stop. While enemies are pursuing you, they don't get Spot bonuses.
A Ranger's Hide in Plain Sight adds to Hide and Move Silently scores, allows Rangers to get closer to enemies and reduces their Spot check opportunity.
Hide now differs from Invisibility. Invisibility is effectively an immunity from Spot checks, provided that the invisible player is greater than 2 meters (approximately one human character body length) from the enemy. For more on important differences between Hide and Invisibility, see the Invisibility article.