Untargetability

Untargetable refers to champions in a state where targeted spells such as and  cannot be cast on the untargetable champion, and nontargeted spells such as will have no effect. Additionally, they cannot be targeted by auto attacks.

Complete invulnerability
These break all forms of leashes and makes the champion invulnerable to all damage.
 * makes him untargetable for a short time before the clone spawns.
 * 's active ability makes your champion untargetable for two seconds.
 * 's passive makes your champion untargetable for (estimated) 3 seconds before revival.

Partial invulnerability
Projectiles fired before the untargetability starts will have no effect. They will still take damage from DoTs such as and  and will not break leashes such as  and. They will not be damaged by and  .They will still take damage from.
 * makes him untargetable for 0.75 seconds or until he uses.
 * makes him untargetable for 2 seconds.
 * makes her untargetable for 2 seconds or until it is recast on an enemy target.

Dashes
Projectiles (autoattacks or abilities) that are mid-flight when the character starts dashing will hit when the dash completes. They still take damage from DoTs while untargetable.
 * makes him untargetable while moving to the target.
 * makes him untargetable for a short time while in flight.
 * makes her untargetable for a short time while in flight.

Damage Invulnerability
Note: The Nexus Obelisk ignores all Damage Invulnerability effects and can damage and kill any champion while the effect lasts.
 * grants the immunity to damage for the duration. DoTs that are still taking effect will continue their damage once ends, and the target can be affected by all forms of CC while it lasts. The unit can still be targeted by attacks and damaging abilities, but will not receive any damage from them.
 * will grant immunity to damage and CC from all sources other than her target. She can still be targeted by attacks and abilities from other sources, but will not take any damage from them, nor will she be affected by any CC from them.
 * will prevent any further damage when he hits 1 hitpoint, but he can still be targeted by attacks and abilities. All forms of CC will still affect him.