Ok working out some starting details of the world for a campaign I am hombrewing for the 1st time. This world is going to have a high celtic theme to it. Druids are therefore going to be fairly dominant in society. My plan was to have there be different druid circles within a grove to add Rangers, Shaman, Hunters, and maybe the new Shifter class in with standard Druids and socially count as Druids. The Shaman would be the Voice of the Spirits, Rangers the Eye of the Hunt, Hunters the Brothers of the Wild, Druids the Soul of the Land, and maybe Shifters will be the Fang of the Beast. Anyway while I intend for class Druids to be in effect the central circle or high priest as they somewhat encompass all the other duties. Still working all this out, but my questions is should I have the other classes also have druidic given to them as a language. On the one hand I am not sure it makes sense to deny it if I am making them culturally one body. On the other hand in game I had intended to give the guy who wants to play a Druid Ohgam Script key and have things written in "druidic" around the world. I now also have someone who wants to play a Shaman. I am now stuck with which is better give them a shared language and not have that be something unique for the druid, or is there a viable reason druidic is just for class druids.
If druids are the high priests within a larger religious body it wouldn't be out of the question for them to have their own secret language- that would be one of things that defined their separate/higher status (and it would function to allow them to keep certain mysteries of the faith secret from the less pure versions of the religion).
In terms of which thing is "better" to give your PCs... allowing one of them to be able to read secrets hidden around the campaign world is better than allowing two of them to have a shared secret language for private conversations. The latter can be accomplished by each spending a rank in linguistics to pick up some obscure language nobody is going to know (like boggard, or sphinx), or to make up their own language for that matter.
I rather like the idea of Druidic being your holy and secret language, because that is just how Druids are.
Druidic Decoder You have a natural understanding of the Druidic language. Prerequisites: Linguistics 1 rank, cannot be a druid. Benefit: You gain a +5 bonus on Linguistics checks made to decipher writings in the Druidic language. If you have 10 or more ranks in Linguistics, add Druidic to the list of bonus languages available to you.
There is no reason you can't add something like this, allowing those of the outer circles to be able to learn Druidic. Perhaps this would be a mark of distinction for them. Note that the rather militant Rangers should have their own Ranger Sign Language.
The way I would handle it would be to allow other classes to be considered druids for purpose of learning the language. There have been many posts on the boards about using other classes to simulate another class. The most common being rogue. If a bard can be considered a rogue why can’t a ranger can’t be considered a druid? This is of course a house rule but it seems reasonable to me. Personally I would say that the class hade to be a divine spell caster.