Presumably because (a) such mental domination is not a sure thing, and (b) stronger-willed individuals are harder to dominate than weaker-willed individuals.But then, why do we grant a dice roll this kind of power over an NPC?
Really? I'd consider it a staple of fantasy/SF fiction that most people immediately succumb to mind control, but a few strong-willed heroes -- and villains -- shrug it off. "Your jedi mind tricks won't work on me."In literature, I often have the impression that there are no "saves" against mental domination.
If you don't think there's any uncertainty to it, you might take the d20 roll out of the equation and have everyone Take 10.
I would agree that help from friends should give the victim multiple saves to break the spell, but I don't think it should be necessary. I'm pretty sure Conan broke an enchantment or two just by being an uncivilized barbarian, free by nature, and I'm pretty sure friends have failed to save the weak-willed against, say, Dracula's charms.Only if your friends try to speak you out of it you get your chance to resist it. And how often does that fail?