Review of Sources
There really are only three sources for this. You’ve got the Baldur’s Gate 1 video game, which is where I think most people would know it from, and then you’ve got both Volo’s Guide to the Sword Coast and the 2nd edition campaign setting.
The video game actually does a much more thorough job of giving this former keep some life. But it doesn’t seriously delve into the background of how exactly this place became an inn, which is sort of funny given that it actually ties into the topics explored in that game quite nicely.
The campaign setting goes into some of the background surrounding the death of Mericor, the priest of Bhaal that once held this place as his hold. Interestingly, it also suggests that troops from southern powers are permitted to place their soldiers here as protection. But neither Volo’s Guide nor the video game explore this further.
The Friendly Arm Inn was once the hold of an evil undead priest of the god Bhaal. The priest was destroyed by (as of 1368DR) an adventuring party led by one of the inn’s current proprietors, Bentley Mirrorshade. He and his wife, Gellana, both gnomes, now run the inn. Gellena, a priestess of the gnome god Garl Glittergold, also runs a temple dedicated to that god within the keep’s fortifications.
It is also said that Bentley is a skilled mage. Volo even believes some of the bar maidens might be iron golems in disguise. The campaign setting suggests this may be the case as well though the video game never touches on it.
What Makes it Unique Compared to Other Settlements?
Assume that it is much more fortified compared to other small settlements in this region. Certainly, it is compared to Gullykin, Ulgoth’s Beard, or Beregost. Its problems are likely more to do with maintaining road security than actually being concerned about the keep falling.
What are the Settlement’s Issues?
Lack of space to grow: this keep likely lacks room for its population to grow. Depending on the inn’s needs, there may be interest in clearly nearby lands for settlement or for farming. That includes hunting monsters that could interfere with this.
Raids: the keep is likely a few days travel from Baldur’s Gate, and it would not have much in the way of any standing force. Volo’s makes no mention of one, and the video game merely has a few guards about to prevent things from getting too out of hand within the keep.
A well-organized hobgoblin or bandit attack could conceivably take this keep. It is just a large stone keep with some stone walls, after all. It is a stone’s throw from both the Cloakwood Forest and Woods of Sharp Teeth’s denizens. There are plenty of different types of enemies that might find the prospect of taking over this place alluring. Likewise, followers of Bhaal may find great satisfaction in wanting to take this place back.
How Can I Use It in My Campaign?
The Friendly Arm Inn makes for a good pit stop. The kind of place that a party might end up in to spend a night. Maybe while they are there, they deal with some of the local problems I’ve outlined above.
Alternatively, it also could be a good starting point for a campaign. Lots of travelers likely make their way through it at one point or another. So it would be a good place for a new party to find themselves meeting and a place where they could find people willing to give them work.