I was planning to start a new dual fighter druid once I've downloaded Baldur's Gate trilogy. The plan was to play a fighter (actually a Berserker) through BG1 and then dual to Druid at some point in BG2 and take the char all the way to ToB.

So I tried making that dual fighter/druid and cheated it up to regaining active in BG2 and something struck me.
When I dual a fighter to druid the druid weapons limitations stay with me while the armor restrictions don't apply. I remember that with a mage all restrictions were gone (except for not being able to spellcast in armor).
So which advantages/weaknesses will a dual fighter/druid actually have?
And how did they implement that into the game? After all a fighter/mage can use Soul Reaver +4 for all they care but the druid can't use a dagger?

Druids are restricted in weapon use due to their vows. Mages are just restricted cause of their lack in training. So a druid will never be able to use twohanded swords cause it goes against their vows. Furthermore, the fighter/druid does have some good weapon choices. For two-handed fighting, the spear and quarterstaff, for single or dual wieldin, the scimitar and club. (there is a rather nice club in the game which also deals acid damage and is +3, good enough, I would say)

I'm aware of all that, I'm just curious how they fitted it into the game. Did they just flag the weapons unusable for pure-mage and anyclass-druid and the armor likewise or is the restriction within the class-data? Not that I want to change it. If I'm going for fighter druid I'll most likely use Dracula's spear (they call him Vlad the ...) as I don't like the clubs' pictures (the one you suggested has a rather cool one but I'd go for the hideously drawn club with the bleeding dmg).

Hard-code :D