According to the in game text on the item. The effect Brilliance of Ro doesn't increase effective casting level. It "decreases chance to fizzle when casting a spell".
Granted, increasing effective casting level would have this effect, but from the in game description, I would conclude that it does not have any affect on the resist rate due to relative level difference between you and what you're fighting.
Of course, for a Bard it doesn't do anything anyway.
i think the main benefit of this effect would be to counter debuffs like the Thought Horror Overfiend, which lowers effective casting level making it impossible to cast any higher lvl spells w/o fizzling. the old strat on that fight was to use spells lvl 40 or lower i.e. CH but with this you could prolly get away with using higher lvl HoTs and patchs ect. of course now theres aa's to counter this. i think your right about this not affecting resists though.
VT was never a zone for people under much under 60. If there were a hard camp limit, why would it be 20 when the effect of the wizard's pet is to raise his skill 12 points AND people who had this item when it was created would have seen no real benefit. There have been some lvl 80 characters formed for testing purposes and this would probably give a typical player the same casting skill of those players.
That being said, this is actually an incredible item for any casting class.
Mages get help with Malosinia - huge help on raids and soloing, Clerics benefit with Marking (also important for raids) Shaman benefit is obvious with slows Druid benefit with debuffs and snares. This would also help on mobs that are almost immune. Chanters with an almost unresistable extended GoD AA mez would own most any situation
I think the point is clear - no matter who gets it, it's raising casting lvl is just an unbelievable advantage.
this effect is pretty much for determining if you get resisted by a mob (which you almost never will, since it puts you 10 levels above even Quarm, which i believe makes it like ur casting on an Lblue, to QUARM) obviously this would have priority to shamans, since not getting resisted is a MUST for them....amazingly powerful tool, i would cry if a cleric ever got this (unless it was gonna rot)
I am unsure about the level hard cap, however, a wizard, using his AA familiar (12 casting levels), and this item at level 65 would be casting at an effective level of 97. Wizards can benefit the most from this item giving them an advantage over any other class... my theory behind this statement... get your wizards these and watch your guild DPS go up just on less resists alone.
A named goo drops this. Hell I dont remember the name of it, everything sounds the same in this zone. Im terrible with names and could take me months get the names of all the loot mobs down. It was the one right before Anten Ha Ra though.
Just to clarify, I got the crown yesterday, and I'm finding the same thing that others have reported, that it's not helping my fizzles at all. It's still very worth it as an item though, gave me 186 HP total.
I was under the impression that "Spell Casting Effectiveness" was merely increasing your role based on level. Wearing this, your odd's of landing a spell would be rolled against yourself + 20 levels. A 65 wizard with this item would be nuking as if he were 85 (plus the number of level's their familiar gives.)