Its goal to bring changes into the life of the island. Mostly beneficial changes, not harmful ones, no one likes being punished all the time (eg. there was a tornado and a few buildings won't work for a day or so or they have to be rebuilt). People would stop playing. But if a few negative events are scattered among a lot of positives then it'll just add variety to the game.
One event could have more than one end result, depending on the player's decisions.
Eg.
- One of the bakers wants a day off because he wants to take his sweetheart out to a picnic. You choose to give him a day free, not expecting anything else to happen. Bread is always needed, so the apprentice is working, some bread is produced, or after his day off, the baker will work twice as hard and produce twice as much bread. But if the baker doesn't get a day off, he'll be depressed and the productivity of the building will suffer from it.
- The blacksmith wants to marry the daughter of the watermiller. If you allow the wedding to take place, some buildings will stop producing for a day or a few hours, but afterwards everyone involved is motivated to produce twice or thrice the usual amount.
- You want to build a new building but while digging out the foundations, they find something strange. The building won't build until it's fully investigated. A few hours later you get mail that they found a gem deposit under the building and you get 100 gems if you pay for the extraction costs (1000 stones and 500 pinewood planks).
- You want to build a wheatfield in place of an exhausted one. The farmer didn't pay attention and forgot to collect the last 100 wheat so when you build it, it'll contain 100 more, or you get 100 wheat and the field will build with a bit of a delay.
- There was a flood, 1 or 2 buildings will stop producing [and get downgraded one level]. Production stops until they are restored but afterwards, it'll work faster (long-term effect - at least longer than a few hours). Because restoring the building can only be done by installing the newest technology, which causes it to be upgraded by two levels -- but at the price of the lower level's upgrade because the insurance pays for the difference.
- the forest is infested with foxes, wild game is abundant this season (event refills all meat deposits with a small amount).
- there is no fish because big predator got into the fishery and eats everything. Delegate settlers to catch it. A few hours later the big fish is caught and it yields almost as many fish as it was lost.
- lightning struck a tree - it's easier to cut down.
- a cold front travelled through sector 7 - it's covered with snow for a week.
- there was a lot of rain - all the cut down tree deposits in sector 8 grew out. How it would annoy those who cut down the trees for the collectibles.
- etc.
The more variety the better. The event can occur rarely in the beginning, but get more frequent if players like it and new ones can be included later. The events should take in consideration the number and type of buildings on the island so as to give the appearance of things happening with the island and not seem like just some generic occurrence to provide an excuse for an action to be taken.