It seems my little human burg of 67 has attracted the ire of the goblins, and come every caravan season 3 or 4 different ambushes spring up consecutively around my wall-less village, making for some challenging gameplay. Having 6 semi-experienced bowmen and as many swordsmen/flailmen helped me a ton, resulting in around one or two citizens getting injured/dying each time, but I feel I've been getting a bit lucky.
See, a common hotspot for attack is the trade depot near the great hall, where the caravan guards usually end up dispatching any threats. But given that my society works almost entirely outdoors, I'm scared to death of a sniper ambush near an area where many tasks are focused (i.e. felling trees, gathering wood, aboveground farming - I have roughly 8 woodcutters and 8 farmers) and thereby an outright massacre occurring.
That's where I'm unclear: Does an ambush first appear at the edge of the map like a siege does, but stays "stealthed" until the ambushers see a hostile target? Or do they spawn at any spot on the map and attack all nearby hostiles? If the former, I'm thinking of a security system where several "outposts" are set up around the perimeter of the map. I draft several civilians of questionable worth as sentries (recruits) and station them in the outposts which are 2 or 3 z-levels high and are accessed via a ladder/stairs to a small windowed room with a trapdoor, which I assume can be locked so the sentry doesn't go running to his death.
Unfortunately none of my migrants came with dogs, so guard dogs are right out, but I'm liking this sentry idea. I'm THIS close to editing horses in the raws so they can be trained into war animals, because goddamn, it's a frickin' horsplosion over here. Thoughts?