Originally posted by Zep Tepi:

Raids - They increase with each boss killed. Some raids are boss+certain creature killed. Your first real worry will be trolls after the Elder plus the first dead troll.

That's where I am right now, though I haven't had a troll actually raid my base yet. I fought my first troll in the Black Forest about 10 minutes after beating the first boss. (I died...3 x, before I got smart enough to use my bow.... Hahah).

I've planted a very thick tree line on the landward side of my base to help when a troll attacks my base...since that first encounter, I have found them pretty darn easy to fight as long as I have a lot of large obstacles like trees to impede them.

My worst side of the base is that it's built on the shore of a lake. I thought it was pretty, but it didn't occur to me that mobs can swim at the time. :(