Types of Crowd Control

There are three fundamentally different categories of crowd control, with most specific forms of CC falling under one or more of them.
 * Movement Modifiers restrict or reduce the target's movement or force a particular move.
 * Slows, Snares, Knockbacks
 * Action Modifiers restrict the target's ability to perform some actions or reduce those actions' effectiveness.
 * Blinds, Immobilize, Silences, Stuns, Knockups, Suppresses
 * Forced Action Modifiers force the target to take a certain action.
 * Taunts, Fears, Charms

Types of crowd control
These are the specific types of crowd control that appear in League of Legends along with a few key notes about each.
 * Blind
 * Makes the target always miss with auto attacks.
 * Most on-hit abilities will be disrupted, preventing them from being used whilst blinded (e.g. ). A few abilities still can be used (e.g. ), but most will miss completely (e.g. ).
 * Some abilities which apply on-hit effects have their damage mitigated (e.g. ).
 * The damage from will miss if he is blinded during the use of the ability.
 * Blind is considered an on-hit effect, and is applied on dealing the damage. As such, attacks already in the air will miss even if the blind is applied after (e.g. The proc).
 * Blind is considered a form of damage mitigation. As such, it is applied after 's passive.
 * Champions with Blind:,.
 * Charm
 * Forces the target to harmlessly follow the source of the charm, making them unable to do anything else, with reduced movement speed. This is similar to Taunt.
 * Will interrupt channeled abilities.
 * Negates all damage from the charmed champion from the moment Charm is applied, including damage that's "in the air".
 * If the target does not have vision of the charm's source, they will simply stand in place.
 * Champions with Charm: .
 * Fear
 * Forces the target to run around randomly with reduced movement speed.
 * Prevents controlled movement, auto attacks, and the use of abilities.
 * Will interrupt channeled abilities.
 * Champions with Fear:, , ,.
 * Immobilize
 * Immobilize is an improved snare, not only preventing movement entirely but also prevents auto-attacks.
 * Movement includes movement abilities, such as dashes, blinks and teleports.
 *  Champions with Immobilize: , ,
 * Knockback / Pull
 * Pushes/pulls one or more units to a different spot against their will.
 * Will interrupt channeled abilities.
 * Cannot be removed by or reduced by Tenacity.
 * Champions with Knockback or Pull: ,, , , , , , , ,  , , , ,.
 * Knockup
 * Knocks the target into the air but does not change their location.
 * Prevents movement, auto attacks and the use of abilities while in the air.
 * Will interrupt channeled abilities.
 * Cannot be removed by or reduced by Tenacity.
 * Champions with knockup:, , , , , , , , ,.
 * Silence
 * Prevents the use of abilities and summoner spells, except for.
 * Does not stop auto attacks.
 * Will interrupt channeled abilities.
 * Champions with silence:, , , , , , , , , ,.
 * Slow
 * Reduces movement speed.
 * Champions with slow:, , , ,, , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,.
 * Snare / Root
 * Immobilizes to prevent movement.
 * Also prevents movement abilities (dashes, blinks and teleports).
 * Champions with Snare: ,, , , , ,.
 * Stun
 * Immobilizes and prevents actions.
 * Will interrupt channeled abilities.
 * Blocks use of most abilities.
 * Champions with Stun:, , , , , , , , , , , , , , , , , , , , , , , , ,.
 * Suppression
 * Immobilizes and prevents actions.
 * Will interrupt channeled abilities.
 * Prevents use of most abilities, including summoner spells.
 * Cannot be removed by or reduced by Tenacity.
 * Champions with Suppression: ,, ,.
 * Taunt
 * Forces the target to try to auto attack the taunting champion, making him unable to do anything else.
 * Will interrupt channeled abilities.
 * Can force movement because target will chase to try to autoattack while taunting.
 * However if the target does not have vision of the taunting champion, he/she will not chase and simply stand in place.
 * Champions with Taunt: ,,.

Removing

 * The summoner spell removes all CC except suppression, knockup and knockback/pull.
 * removes all forms of CC including suppression, except knockup or knockback/pull.
 * removes all forms of CC including suppression, knockup and knockback/pull.
 * removes all forms of CC including suppression, except knockup, knockback/pull and blind.
 * will continue to do damage.
 * The active on removes all forms of CC including suppression, except knockup and knockback/pull.
 * removes all slows. It also reduces the duration of new slows by 50% for the duration of the ability.

Preventing

 * prevents all forms of CC for 5 seconds or until the shield is broken.
 * prevents all CC for 6 seconds, including suppression, silence, blind, knockup and knockback/pull.
 * prevents slows for (6/9/12) seconds.
 * creates a magical barrier for 3 seconds which can block the next enemy spell that hits her.
 * creates a magical shield for 2 seconds which can block the next enemy spell that hits him.
 * creates a spell shield that can block a spell once every 45 seconds.

Reducing
Note: Duration reduction has no effect on suppression, knockup and knockback/pull.

Tenacity
The reduction from the Tenacity stat on items does not stack with itself and stacks multiplicatively with other types of CC duration reduction from the champion abilities.
 * reduces the duration of CC by 35%.
 * reduces the duration of CC by 35%.
 * reduces the duration of CC by 35%.
 * reduces the duration of CC by 35%.

Champion abilities

 * reduces the duration of CC while active by (15/20/25/30/35)%.
 * reduces the duration of CC by (10/25/40)% for (1/2/3) nearby enemy champion(s).
 * reduces the duration of CC by (10/15/20)% for 25 seconds.
 * reduces the duration of CC while active by (20/25/30/35/40)%.

Masteries

 * reduces the duration of CC by 10%.