Roulette

Roulette (死のルーレット) is a Blue Magic spell. It casts Death on a randomly chosen target on the battlefield, enemy or ally. In order to successfully learn the Roulette spell, the targeted character must generally be under the Auto-Life or NulDeath status to survive the instant death.

Final Fantasy V
Roulette is a Blue Magic spell the Blue Mage can learn from Azulmagia, Death Dealer, Parthenope, and Shinryu. The spell costs 1 MP to cast. A minor glitch in the game prevents the player from seeing the Roulette cursor if they attempt to target a party member or enemy with any sort of action while Roulette is being used.

Final Fantasy VI
Roulette is a Lore for Strago that costs 10 MP to cast, an ability of Gau when raging Ahriman, or Gogo when using either command. When used via Rage, Roulette will lose its random targeting aspect and target enemies like any normal attack spell would, as its random nature comes from an automatically moving cursor, something Rage does not supply. Strago can learn Roulette from the Ahriman, Alluring Rider, Dark Force, Nelapa, and Onion Knight.

Enemies attempting to use the Lore cast a variant of the spell instead. This variation heals the undead, whereas the Lore/Rage version does not.

Final Fantasy VII
Roulette is an Enemy Skill learned from the Death Dealer. It costs 6 MP to cast. The units' Luck appears to affect the chance of the spell hitting; a party with high enough Luck is virtually never hit by the spell, which can make it annoying to learn.

Final Fantasy IX
Quina can learn Roulette from the Ghost, Hecteyes, and Zombie, and it costs 18 MP to use.

Final Fantasy Tactics Advance
Learned from Ahrimans as a Blue Magic spell, Roulette will instantly KO a random unit excluding certain bosses at the cost of 20 MP. In order to learn this spell on a Blue Mage, the learner must have the Auto-Life status on in order to survive the attack and learn it.

Final Fantasy Tactics A2: Grimoire of the Rift
Roulette is a Blue Magic spell learned by Blue Mages from Ahriman-type enemies, which costs 12 MP to cast. To successfully learn this skill, the Blue Mage must be under Reraise-status and be hit by it, however, the random target of the spell makes it difficult to learn.