I would imagine it is PG 13 because the platform we use, NWN2.
This is NWN2's EULA:
EDITOR AND END-USER VARIATIONS If the Software includes a feature that allows you to modify the Software or to construct new variations (an "Editor"), you may use such Editor to create modifications or enhancements to the Software, including the construction of new levels (collectively the "Variations"), subject to the following restrictions. Your Variations: (i) must only work with the full, registered copy of the Software; (ii) must not contain modifications to any executable file; (iii) must not contain any libelous, defamatory or other illegal material, material that is scandalous or invades the rights of privacy or publicity of any third party; (iv) must not contain any trademarks, copyright-protected work or other property of third parties; and (v) may not be commercially exploited by you, including but not limited to making such Variations available for sale or as part of a pay-per-play or timesharing service.
Under point 3 you can see that you cannot infringe the right of privacy or publicity of another party. And point 4 protects third party copy right.
I would guess that the D&D Forgotten Realms licence NWN2 came with is PG-13. That seems to be the standard Wizards of the Coast policy with novels and games. So while NWN2 itself doesn't appear to require PG-13 content restrictions, the setting we use is likely to require it.
So its important to distinguish that there are multiple licences we are dealing with here. One for NWN2 itself, and one for the D&D setting we use.
Now technically it might be possible to argue that BGTSCC does not use a 3.5 or 4.0 D&D setting licence because our server is set in the perior prior to AD&D second edition. So that we wouldn't be restricted by the default licence the game came with. And you could also argue that we aren't infringing the licence since BGTSCC is not a commercial gaming product.
But you still run the risk of making negative publicity for the company that owns the D&D franchise, and causing them damage. So while its certainly not clear if we are using a licence, its simple human decency to avoid harming their product.
Imagine for example that a new player breaks this rule and proceeds to do erotic roleplay of some sort with a minor. If that sort of thing somehow ends up in the public domain and this server did not have rules against it it would look very bad. You would not want that associated with your products if you own the D&D franchise. Because that's probably what the headlines would be. (which I will refrain from illustrating with an example)
So the best thing for all our sakes and peace of mind is to keep the setting PG 13.
