Adding Brown Sugar

Brown Shugga!
I wanted to incorporate brown sugar into my brew and was wondering whats the typical results. Does the all the sugar ferment and you obtain a dryer beer or does it have unfermentables and increase sweetness of the beer. I'm hoping that the brown sugar could add another level of flavor.
When do you think it should be added? I was thinking last 15 minutes of the boil, or does it not have any bearing?

Sugar dries a beer out if it is used as a replacement for another ingredient.
If it is and adition it will give a higher ABV with out adding body.
It will impart a flavour.

Yes it can be added at 15 minutes.

If you're looking for that flavor, a small amount of molasses or treacle will give it to you without significantly changing your ABV. I like to add a few tablespoons to my brown ale.

I've used brown sugar and added it at the last 15 minutes or so. What I found is that it adds rum like notes to the beer. I used 4 ounces and, according to my notes from Xinghu (spelling?), it was excellent, coffee type notes, along with the rum characteristics. I'd use it again. I've never used treacle, but tasted a beer with it and didn't care for it. I found that molasses didn't add the same flavor profile as brown sugar did. Don't forget, there are different 'colors' of brown sugar. Use the darker one for darker beers.

The sugar in Brown sugar is 100% sucrose and 100% fermentable, so it won't add sweetness to the batch. The molasses in the sugar will add new flavors.

I used it in a stout beer a couple of years ago and gave me a good result