Multi-Target

Multi-target means targeting a spell on multible allies/enemies.

Final Fantasy
Multi-target can't be toggled, but some spells target multible enemies.

Final Fantasy II
Every spell in the game can be multi-targeted.

Final Fantasy III
Most spells can be multi-targeted, but some can't.

Final Fantasy IV
Same as in Final Fantasy III

Final Fantasy V
Same as in Final Fantasy III

Final Fantasy VI
Same as in Final Fantasy III

Final Fantasy VII
Most spells can be multi-targeted by having the Materia attached to an All Materia.

Final Fantasy VIII
Final Fantasy VIII returns to the way the original works, in that spells either target one are all targets.

Final Fantasy IX
This game returns to the system used in Final Fantasy III

Final Fantasy X
Returns to the system used in the original and VIII

Final Fantasy XI
Because there is no battle screen, certain spells target all characters in an area.

Final Fantasy XII
Works in the same way as XI

Final Fantasy XIII
There is a battle screen, but certain abilities animation happens in an area, and all characters of the target's side get hit.