I'd rather be more restrictive and have a specific unit type cast it, to put a slight limitation on those spells as well as making it more flavourful and making it less likely for the spell to be cast by mistake.
Some powerful worldspells could even be limited to late or rare units to balance their power. This would make unlocking them one priority among many, and add strategic choices.
ex:
Amurite's Arcane Lacuna -> Archmage
Calabim River of Blood -> Vampire Lord
Clan's For the Horde -> any melee unit
Doviello's Wild hunt -> hunter
etc...
Note that those choices are not very restrictive, since you usually have those units by the time you want to use the worldspell.
And to the OP, how do you not have any units?
Also, I can't tell you how many times a dumb klutz like me inadvertently hit the WorldSpell unit on a unit. Sometimes before you click the screen moves a tad and you hit the wrong button. (this also happens to me with the declare nationality button).
Of course, you do get that 'do you really want to do this?' prompt, but I know at least twice I responded affirmatively not thinking of what I was doing.
Bam, one WorldSpell gone.![]()
Fortunatly there is already a "are you sure?" popup.oh yeah, I forgot about that. it did not happen to me yet to waste my preciousssss worldspell due to misclicking, but that's just BOUND to happen - sooner or later
Fortunatly there is already a "are you sure?" popup.