Smoke

Smoke, also known as Smoke Bomb, Smoke Screen, and Dustb, is a recurring ability in the Final Fantasy series. It is a type of Ninjutsu magic, and is sometimes an item. When used it allows the party to instantly escape from battle, and less commonly inflicts Blind on enemies.

Final Fantasy IV
Smoke, known as Smokebomb in the J2e translation, is a Ninjutsu spell usable by Edge, which he learns at level 33 in all versions. It has a casting time of 0, costs 10 MP (5 MP in the 3D version). In the GBA version, a glitch may cause the Smoke particle effect to not appear on all characters, though the ability has succeeded.

Final Fantasy IV -Interlude-
Smoke returns as a Ninjutsu spell in the sequel of Final Fantasy IV and Edge already known the spell. It allows the party to escape from random battles at the cost of 10 MP.

Final Fantasy V
Ninjas have !Smoke, also known as Dustb, which is a Level One command ability that instantly has the party escape from battle. It requires 10 AP to learn.

Final Fantasy XI
The Ninja can use Kurayami: Ichi and Kurayami: Ni, which inflict Blind on enemies to reduce their accuracy. As a reference to the Smoke Bomb item, the item required to use the two abilities is a Sairui-ran, which bears an approximate meaning of an egg-shaped tear gas bomb.

Final Fantasy XIV
Smoke Screen is a level 52 Ninja ability. It creates a wall of smoke, reducing enmity generation of a single party member.

Final Fantasy Dimensions
Smoke Bomb is the level 13 ability of the Ninja class, requiring 325 AP to learn. At the cost of 10 MP, the user will force the party to flee from any fleeable battle.

Ehrgeiz: God Bless the Ring
Smoke Bomb is Yuffie's Special ability, used by pressing the jump button and hitting the Special button afterwards. Yuffie will jump into the air and throw a smoke bomb at the opponent, knocking the opponent down while making the opponent vulnerable to attacks for a short period of time.

Etymology
The ability's existence is based on the common depiction of ninjas in fiction, where they often use explosive powders to create bursts of smoke to distract and blind their enemies.