That moment when you realize that druid and cleric are indeed 3/4 BAB classes... I replaced clerics with my setting with the Cloistered variant, my bad, and I completely forgot druids
Could make it down to +10 letting high level wizards get it, along with druids ~16th and a fighter @ 10th... I mean auto succeed should never be on a spell IMO.On the other hand clerics and druids getting immunity would happen at very high level and fighters would get immunity as early as level 15(and before level 15 most fighters would fail a great portion of the time grapple checks against colossal scorpions)