Who can cast a circle of protection

[Ankhr]

I was creating a weapon for a character and started tthinking. Could a character that would be affected by a protection circle cast one. I know a greater supernatural being, like a godling, can cast protection simple as they aren't affected. But could a Godling cast protection superior? I think yes. I think if that was a limitation it would be stated.

[Library Ogre]

Yes. I would say that the creator of a circle is immune to his own protection circle, in most cases.

[drewkitty ~..~]

The protection any circle gives is to 'the people/beings inside the circle' from 'things outside the circle'. If the attacker is already inside the circle then there is no protection given to the target of the attack.

[eliakon]

Not a problem.
You start out either inside or outside the circle of course. Either way you can cast the spell with out a problem (I believe that there are some NPCs who have the spell and are subject to it)

It would be up to the GM if you are immune to your own spell or not. My personal opinion is that in general you are affected by your own magic unless there is a specific statement saying you are not.

[Axelmania]

I think the best guideline here would be how "Sealed" circles work for Palladium Fantasy's "Circle Master" Summoner OCC on page 138.

I can't see anything which would allow normal protection circles to be entered by the summoner who created it if they are among the things the circle protects against...

But then:

Circle Master can "seal" his circle by placing a few drops of his own blood in a small circle
..
The circle maker can list the specific people who can enter and use his circle by inscribing their true name, or by using a drop of their
blood.
Or the mage can limit the availability of the circle to a broader range of beings by indicating with a magic symbol that it can be used
by those of good or evil alignment, demons, witches, etc.
In either case, the circle must be sealed with the mage's own blood

I can't see the Lesser or Greater Circle of Protection (mere spells a plethora of casters could do) as somehow having more fine control than a Circle Master...

So I think if a supernatural being wanted to enter their own circle, it should have similar requirements. Either a few drops of blood or inscribing their true name.

That or just don't allow it at all, it's still useful to be able to create circles for your mortal friends' protection even if you cannot personally benefit.

[eliakon]

I think the best guideline here would be how "Sealed" circles work for Palladium Fantasy's "Circle Master" Summoner OCC on page 138.

I can't see anything which would allow normal protection circles to be entered by the summoner who created it if they are among the things the circle protects against...

But then:

Circle Master can "seal" his circle by placing a few drops of his own blood in a small circle
..
The circle maker can list the specific people who can enter and use his circle by inscribing their true name, or by using a drop of their
blood.
Or the mage can limit the availability of the circle to a broader range of beings by indicating with a magic symbol that it can be used
by those of good or evil alignment, demons, witches, etc.
In either case, the circle must be sealed with the mage's own blood

I can't see the Lesser or Greater Circle of Protection (mere spells a plethora of casters could do) as somehow having more fine control than a Circle Master...

Exactly.
Especially with out having any statements mentioning any such control, yet having to call out such rules and limits on True Circles.
I would say that these spell circles are basically crude approximations of the Real Deal (think an invocation conversion of the actual CoP) and that as such they are not nearly as fine tuned.
And as there is, as far as I know, no provision that allows a mage to walk through their own wall of force or to not be burned by their own wall of fire or that their own amulet given to another will not provided a +1 to save against the casters own spells, or a weapon enchanted by the mage will not do increased damage to the mage I likewise see no reason to grant this one spell a unique, but totally unmentioned, special ability of being immune to the regular rules and not affecting the caster in any way.