A 
channel is a trait of certain abilities that causes the caster to become occupied for a period of time in which they must delay the effects of a spell to trigger them afterwards or maintain them over the duration.
Channels are capable of allowing or preventing the caster from performing certain actions, including moving, declaring attacks, casting abilities, using summoner spells, or activating items.
Interrupting Channels
Channels can be interrupted to cancel the spell entirely. The caster may be able to interrupt their channel by performing certain actions, depending on the spell.
All channels are interrupted by the following forms of 
crowd control: 
airborne, 
forced action, 
silence, 
sleep, 
stasis, stun, suspension, and 
suppression. These crowd control effects disable casting and will therefore interrupt channels. Disrupt is a special form of crowd control that specifically interrupts channels.
Movement channels, or those that cause the caster to move (by either 
dashing or 
blinking or other forms of movement), are also interrupted by 
root and 
ground. This may be case by case depending on the spell.
Objective channels, or those that require the caster to be out of combat, are also interrupted upon taking damage.
Channels can be set to not be interruptible, meaning none of the crowd control effects stated above would affect the channel's status. Note that entering a 
death or 
resurrection state will cancel all ongoing actions, including channels.
Spells not interrupting Channels
The following abilities and item actives do not interrupt channels by any means when they are used, except when the channel in question is cancelled by certain conditions (such as moving):
Annie's Summon: Tibbers (recast)- Aatrox's Umbral Dash
- Aurelion Sol's Starsurge (recast) and Celestial Expansion
- Gwen's Skip 'n Slash
- Illaoi's Harsh Lesson
- Irelia's Flawless Duet (recast)
- Ivern's Daisy! (recast)
- Lucian's Relentless Pursuit
- Pantheon's Aegis Assault (recast)
- Rell's Attract and Repel (recast)
- Samira's Wild Rush
- Sejuani's Arctic Assault
- Shaco's Hallucinate (recast)
- Sion's Soul Furnace (active and recast)
- Swain's Nevermove (recast)
- Taliyah's Weaver's Wall (recast)
- Urgot's Purge (recast) and Fear Beyond Death (recast)
- Varus' Blighted Quiver (active and recast)
- Vi's Relentless Force
- Viego's Harrowed Path
- Vladimir's Sanguine Pool
- Warwick's Primal Howl
- Yuumi's You and Me! and Zoomies
- Zoe's Paddle Star and Spell Thief
- All consumable items (excluding Eye of the Herald)
- All trinket items
- Gargoyle Stoneplate
- Randuin's Omen
- Shurelya's Battlesong
- Turbo Chemtank
- Youmuu's Ghostblade
List of Channels
Normal Channels
- Champion abilities
- Akshan's Comeuppance
- Caitlyn's Ace in the Hole
- Corki's The Package
- Fiddlesticks' Bountiful Harvest
- Gragas' Drunken Rage
- Ivern's Friend of the Forest
- Janna's Monsoon
- Jhin's Curtain Call
- Karthus' Requiem
- Katarina's Death Lotus
- Kayn's Umbral Trespass
- Lucian's The Culling
- Malzahar's Nether Grasp
- Master Yi's Meditate
- Miss Fortune's Bullet Time
- Nunu's Absolute Zero
- Quinn's Behind Enemy Lines
- Rammus' Powerball
- Vel'Koz's Life Form Disintegration Ray
- Warwick's Infinite Duress
- Xerath's Rite of the Arcane
- Yuumi's Prowling Projectile and Final Chapter
- Item actives
- Other
- Elementalist Lux's element shift
Movement Channels
- Champion abilities
- Fiddlesticks' Crowstorm
- Galio's Hero's Entrance
- Nunu's Biggest Snowball Ever!
- Pantheon's Grand Starfall
- Shen's Stand United
- Sion's Unstoppable Onslaught
- Tahm Kench's Abyssal Dive
- Taliyah's Weaver's Wall
- Twisted Fate's Gate
- Ryze's Realm Warp
- Vi's Vault Breaker
- Warwick's Jaws of the Beast
- Yuumi's You and Me!
- Zac's Elastic Slingshot
- Summoner spells
- Spells
- Other
Unstoppable Onslaught and 
Grand Starfall (second channel) both grant 
crowd control immunity to the caster during their channels, therefore they could not be interrupted by crowd control.
Objective Channels
- Champion abilities
- Spells
- Other
Uninterruptible Channels
Irelia channeling 
Defiant Dance even after being suppressed.
- Champion abilities
- Aurelion Sol's Voice of Light
- Irelia's Defiant Dance
- Pantheon's Aegis Assault and Empowered Aegis Assault
- Urgot's Mercy
- Item actives
Charged Abilities
Xerath charging up 
Arcanopulse to increase the range of the beam he is about to fire.
A charged spell has an active and a recast. The activation causes the caster to initiate a channel in which they charge up over a specified time during it as a means to increase the spell's effectiveness. The recast can be used to end the channel to trigger the spell's effects.
Charged spells will cancel if the channel's duration permits. If stated otherwise, the recast will be automatically used.
Charging is a sub-classification. The forms of crowd control that interrupt a charged spell depends on the type of channel.
- Champion abilities
- Summoner Spells
Channel Interactions
The following channels cause the caster to be unable to cast some or all of their abilities and/or issue attack commands, but still allows them to issue movement commands.
The following channels cause the caster to become unable to issue movement commands, but still allows them to cancel the channel early by other means.
The following channels cause the caster to become unable to issue movement or attack commands or cast abilities, in addition to not allowing them to cancel the channel early.
- Aurelion Sol's Voice of Light
- Caitlyn's Ace in the Hole
- Fiddlesticks' Crowstorm
- Galio's Hero's Entrance
- Karthus' Requiem
- Pantheon's Grand Starfall (both first and second channels)
- Shen's Stand United
- Tahm Kench's Abyssal Dive
- Taliyah's Weaver's Wall
- Twisted Fate's Gate
- Warwick's Infinite Duress
- Yuumi's You and Me!
- Teleport
- Eye of the Herald
In contrast to the above, the following channels do not necessarily prevent the caster from performing actions but will automatically cancel when they do so for all or certain actions:
- Corki's The Package
- Fiddlesticks' Bountiful Harvest
- Ivern's Friend of the Forest
- Janna's Monsoon
- Jhin's Curtain Call
- Katarina's Death Lotus
- Malzahar's Nether Grasp
- Master Yi's Meditate
- Miss Fortune's Bullet Time
- Nunu's Absolute Zero
- Ornn's Living Forge
- Rammus' Powerball
- Vladimir's Tides of Blood
- Xerath's Rite of the Arcane
- Yuumi's Prowling Projectile
- Zilean's Time in a Bottle
- Hexflash
- Recall
Ryze's 
Realm Warp is the only channel that does not disable any actions and prevents the caster from cancelling it early.
Casting Times
A majority of abilities and item actives have a casting time, during which time the caster cannot move, attack, or cast other abilities but will instead buffer them to be issued at the end of the cast time. Cast times will pause all previous actions until they complete, although some may interrupt them as whole.
Cast times cannot be interrupted by any means except by death. Anything occurring after the completion of a cast time will take place regardless of the caster's circumstance.
Note that spells may have both a cast time and a channel, with the former always occurring first. If the caster is unable to cast abilities when the cast time completes, the channel will not start.
