Stealth

Stealth is the ability of certain champions to become invisible for a determined period of time. Riot is in process of retooling stealth.

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.

Items

 * Ward from
 * Ward from
 * Ward from

Champions
The main two stealth champions, and, possess long-term stealth but are currently undergoing a stealth overhaul.
 * will stealth her until the Twilight Shroud ends or Akali steps outside of Twilight Shroud. Whenever Akali casts an ability or autoattacks inside of Twilight Shroud, she is revealed for .5 seconds. The also gives bonus armor and magic resistance for 10 / 20 / 30 / 40 / 50.
 * allows her to enter stealth after 1.5 seconds of casting for 10 / 20 / 30 / 40 / 50 seconds. The next attack or damaging ability she uses will pull her out of stealth and will slow her target by 30 / 35 / 40 / 45 / 50 % for 3 seconds.
 * will immediately stealth him for 3.5 seconds and teleport him in medium distance. Note that he blinks after stealthing, thus the enemy team cannot estimate direction he went without stealth detection.
 * will stealth him for 2.5 seconds and gives him 40% increased movement speed. If Talon breaks the stealth, The blades around Talon will converge and return to Talon, Dealing 150/225/300 damage to any unit it pass through.
 * will stealth him until he moves or attacks if stand still for 2 seconds. If Teemo breaks the stealth, he gains 40% bonus attack speed for 3 seconds.
 * allows him to enter stealth after 1.25 seconds of casting for 10 / 20 /30 / 40 / 50 seconds. If Twitch attacks or casts a spell while stealthed, he loses stealth but gains bonus attack speed of 30 / 40 / 50 / 60 / 70 %. This attack speed bonus has duration equal to double the amount of time Twitch was stealthed before attacking, to a maximum duration of 10 seconds.
 * will stealth him for 1.5 second and leaves an uncontrollable decoy that deals 70 / 115 / 160 / 205 / 250 magic damage after 1.5 second.
 * gives her increased attack damage 25 / 40 / 55, a 1.5 second stealth after using and triple the bonus movement speed for.

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:

Items

 * Vision Wards can be purchased at the item shop for 125 gold. 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 (400g) 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:
 * and
 * will provide semi-reveal. Though stealthed unit will still be immune to autoattacks and targeted spells, Duskbringer's trail will compromise position of said unit for 5 seconds, even through movement.
 * and
 * will provide semi-reveal. Though stealthed unit will still be immune to autoattacks and targeted spells, Duskbringer's trail will compromise position of said unit for 5 seconds, even through movement.
 * will provide semi-reveal. Though stealthed unit will still be immune to autoattacks and targeted spells, Duskbringer's trail will compromise position of said unit for 5 seconds, even through movement.

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.
 * will explode but not reveal stealthed champions.
 * does not reveal stealthed champions but if they are within range and below half health, he will receive the movement speed bonus.
 * can detect stealthed champions due to the particle effect flying in their direction. The stealthed champion will not be revealed.
 * will explode but not reveal stealthed champions.
 * does not reveal stealthed champions but if they are within range and below half health, he will receive the movement speed bonus.
 * can detect stealthed champions due to the particle effect flying in their direction. The stealthed champion will not be revealed.
 * does not reveal stealthed champions but if they are within range and below half health, he will receive the movement speed bonus.
 * can detect stealthed champions due to the particle effect flying in their direction. The stealthed champion will not be revealed.
 * can detect stealthed champions due to the particle effect flying in their direction. The stealthed champion will not be revealed.

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 short of its trajectory and show visual and audio effects (eg. will make a splatter and show a small eruption of blood upon impact) if a stealthed unit is hit, indicating the stealthed champion's presence but not reveal them. Here are some more ways to detect stealthed enemies since they'll function the same as if they are unseen in brush.
 * will visibly entrap the stealthed champion without revealing the champion.
 * will visibly entrap the stealthed champion without revealing the champion.
 * can still missle lock on stealthed champions if hit with . You won't see the champion but you can see the debuff animation and follow it with your mouse.

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.

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

It has been revealed that the current testing for the stealth overhaul will result in a permanent stealth state for and  once they put one point in the appropriate skill. From that point, they will remain in a stealth at all times and only be revealed when they perform an action (attack or use an ability). They will be revealed by stealth revealing as normal, but also when they approach enemy champions at a reduced distance than normal vision like. This will allow them to travel between lanes, past minion waves and s without detection but won't be able to walk around with the enemy team undetected anymore.