Spell shield blocks all components of an ability including crowd control, unless otherwise stated.
EditA unit is made airborne alongside undergoing a forced displacement in a specified direction or to a specific point. For the duration, the unit is also stunned and cannot move, attack, cast abilities, activate items or use the summoner spellsFlash, Teleport, Hexflash, and Mark / Dash.
The forced movement that comes with airborne effects cannot be removed by cleansing effects. However, Cleanses can be used to remove the underlying stun, allowing the user to cast abilities: a dash or blink ability can be used to overrule the forced movement. Note that Cleanse and Mikael's Crucible, specifically, cannot be used to do this.
To expand upon the countering of airborne effects, consider that the effects are made up of two components: a movement modifier (called a "move block" by Riot, referring to a chunk of code) and a stun (which is responsible for disabling the actions of attacking and casting). As a general rule, the most recent move block will over-rule any previous move blocks, which is how Alistar'sHeadbutt and Pulverize combo functions. This rule also extends to all beneficial movement modifiers, such as dashes and blinks, which is why Rocket Grab and Rocket Jump will over-rule each other depending on their order of activation. Most beneficial movement modifiers do not prevent the activation of abilities, allowing Tristana to still activate abilities during Rocket Jump but not during Rocket Grab.
In some instances, the stun duration is longer than the move block (e.g. Sion'sUnstoppable Onslaught), but in most cases they are the same duration. There have been cases in the past where the stun duration was shorter, but this usually lead to bug-like interactions and was later "fixed" (e.g. Azir'sEmperor's Divide did not apply any stun at all in the initial charge on the ability, which allowed his enemies to use an instant movement ability to supersede the charge's knockback and get over the wall).
The target is made airborne in a direction perpendicular from the source.
EditA unit that is blinded will "Miss" their basic attacks, similar to when attacking a target with dodge or block. Missed attacks will fail to deal damage or apply on-hit effects, with the exception of some empowered basic attacks. Unlike Disarm, Blind does not prevent the unit from declaring attacks.
Blind causes Graves' shotgun to fire pellets with a random spread, excluding the direction of his target.
Does not interrupt any abilities, but will prevent on-hit effects from being triggered unless otherwise stated. This does not consume the effects, however, (provided they are consumed on-hit) and they will simply wait until a successful attack lands or their buff times out.
EditA unit that is charmed will walk toward the Source (the unit that casted the Charm spell) for the duration, during which time they cannot control their own movement or attacks, and cannot cast abilities, activate items or use the summoner spellsFlash, Teleport, Hexflash, and Mark / Dash. All charms also apply a slow, with the strength depending on the spell.
EditA champion that is fleeing or feared will move directly away from the Source (the unit that casted the Fear spell) for the duration, during which time they cannot control their own movement or attacks, and cannot cast abilities, activate items or use the summoner spellsFlash, Teleport, Hexflash, and Mark / Dash. All fears also apply a slow. Non-champions affected by Fear will instead move around aimlessly.
Uniquely to Volibear, fear slows the target by 100% which causes it to stay in place instead of away from the Source.
EditA unit that is taunted will attempt to perform basic attacks on the Source (the unit that casted the Taunt spell) for the duration, during which time they cannot control their own movement or attacks, and cannot cast abilities, activate items or use the summoner spellsFlash, Teleport, Hexflash, and Mark / Dash.
EditA unit that is grounded is unable to activate mobility spells, which include all active dash and blink abilities, plus a number of additional cases. The effect does not innately knockdown a target that is already performing a dash or blink.
Ground is the only type of crowd control that is most commonly found in persistent area of effects, which will reapply the status effect continously.
EditA unit that is nearsighted has their sight radius reduced and loses their allied and other external vision (i.e. their ability to see what their allies see; wards and traps; abilities that grant vision; unobstructed vision). This means it prevents unit-targeted effects, such as basic attacking, from being used outside of the unit's reduced sight radius, requiring the unit to have personal vision of their target. The allied portrait icons do not update while nearsighted unless an ally dies; the health, resource, and ultimate indicators do not change from at the time of being nearsighted initially. True sight does not infiltrate nearsight. Multiple applications of nearsight debuffs will only consider the one with the greatest sight reduction.
EditA unit that is slowed has reduced movement speed for the duration. Slow percentages cannot reduce a target below 110 movement speed. Some slows will instead modify the target's movement speed to a static value, which may not be further reduced nor increased.
Only the slow with the highest value is taken into movement speed calculations. All additional slows are ignored until the higher-valued slow wears off.