Stealth

Stealth is the ability of certain champions to become invisible for a determined period of time.

Gameplay
Stealthed units will fade and/or disappear from enemy sight until they have been attacked, or the duration of their invisibility effect expires. For some champions, using an ability that will cause them to become stealthed is preceded by a period called a "fade time", during which the champion appears partially transparent, but is still visible to enemies. During this fade time, any damage taken by the champion delays becoming invisible for a short period of time. No matter how many times a champion is hit, however, the fade time on invisibility cannot exceed five seconds. Summoner spells can be used during stealth without breaking it.

Invisibility detection
There are various ways for a champion to gain the ability to see invisibility. A champion with this ability will see invisible enemy units as partially translucent. When a revealed invisible unit leaves the revealed area that unit does not experience a fade time; the unit immediately turns invisible again. The following is a list of possible ways to detect invisible Champions:


 * Vision Wards can be purchased at the item shop. When placed on the ground these stationary wards reveal an area of the map for three minutes. Any invisible enemy units who move through their vision radius during this time will be revealed.


 * A consumable potion available at the item shop that grants invisibility detection to a champion until death. Any invisible enemies enter this champion's vision range while this potion is active will appear to be revealed.


 * Champion Abilities: The following abilities can reveal invisible units for a period of time:


 * Presence Detection without Reveal:
 * All abilities that do not require single target casting will affect stealthed champions but will not reveal them. These abilities can only be cast if an enemy is in range of the AoE casting circle, so seeing the ability available can indicate a stealthed champion nearby.
 * also does not reveal stealthed champions but if they are within range and below the health threshold, he will receive the speed buff thus indicating their presence.
 * also does not reveal stealthed champions but if they are within range and below the health threshold, he will receive the speed buff thus indicating their presence.
 * also does not reveal stealthed champions but if they are within range and below the health threshold, he will receive the speed buff thus indicating their presence.
 * also does not reveal stealthed champions but if they are within range and below the health threshold, he will receive the speed buff thus indicating their presence.
 * also does not reveal stealthed champions but if they are within range and below the health threshold, he will receive the speed buff thus indicating their presence.


 * Skill Shots:
 * While skill shots that do damage and/or stun such as  will still hit stealthed champions, they will still not be revealed.
 * Note that the visible projectile will stop if a stealthed unit is hit, indicating the stealthed champion's presence but not revealing them.


 * Forcing Enemies out of Stealth:
 * Taunting a stealthed enemy will cause him to attack, automatically revealing him and forcing him out of stealth. This can work if you target a visible stealthed unit or if the enemy is currently entering into stealth. With AoE taunts, such as  or , this is easier as you can force every stealthed champion in the area to attack, even if they are invisible.

Stealth Overhaul
A rework for the stealth system is currently planned by Riot. The goal of the rework is to create a non-binary stealth system: in the current system, in fact, a champion which can stealth himself for a long time in a non-limited area like and especially  is too powerful if the enemy team didn't buy an  or some s but too weak otherwise. This effect is particularly frustrating for new players who don't know how to counter stealth. Another weak point of the current system as stated by Riot is the ability for champions with long stealths to scout the map with no risks involved, granting their team a huge advantage in map awareness.

and reworks have been put on hold while the stealth system gets changed. No date has been announced yet for the release of the new system.