(First post on the forums. Heya!)
My idea first would involve the creation of campfires that are currently within Adventurer mode within Fortress mode. After this feature is implemented, then my idea will be possible; The creation of large towers (similar to lighthouses) called Beacons, which light up the night sky.
Beacons would be large structures built at least 6 Z-Levels above the ground to have an affect. They have a similar system to the office/room worth system, but except for their price and noble value, a higher quality beacon room will lead to higher quality in affects, both good and bad.
The main defining factors for beacon construction are;
A. Their amount of windows. Say, a fireplace is made in the center of a room. It only has 1 window. That would be low-quality. However, if the beacon room's walls were almost entirely made up of windows, then it would be much better.
B. The windows' borders to the outside limits of the map. Say, a the fortress builds a tower 10 Z-levels high in order to craft a beacon. They then build a tower 12 Z-levels high for jails. The beacon will have a bit less quality then, due to being unable to be 'seen' behind it.
C. The room's look and wealth amount.
These affects will alter the beacon's effectiveness. There are five central effects from building a beacon;
1. Larger migrant waves. Perhaps you get an addition of 1-7 extra dwarves per migrant wave when you have a beacon.
2. Less ambushes and thieves. Think in the mind of a thief; What is easier to take down, a little hole in the mountain, or a little home in the mountain that has a massive fucking glowing tower sticking out of it?
3. A bit of a better chance for off-site holdings to be made due to your reputation. A beacon would be a safe symbol that the fortress is alive and functional, so it would attract a large bit of attention.
4. Larger and more frequent sieges. When you have a beacon, it has the same affect on goblins- showing your location and that you're alive. And where there's life, there's treasure and potential wealth. And if they had enough materials to build a structure like a beacon, it'd be fairly reasonable to make a larger force in case they are especially dangerous, hm?
That's my idea. Please tell me what you think of it!