[Molly]

With our particular theme in 4D, time-travelling, we actually have a somewhat logical explanation for the repetivity of most Mud activities. When the player returns to an area, the time will have reverted to some period before he last visited, which accounts for the fact that all the baddies he killed are now very much alive again and don't even seem to remember him. This also gives me an excuse to make my quests repeatable - not that I really need one.

As a Builder I dislike one-time quests, since so much work gets into designing and scripting a good multistep quest that it seems a waste of time, if the players only can do it once.
And our players also hate one-time quests - we do have a few of those, but they keep complaining and asking that we make them repeatable.

My solution is threefold - (and this also to some extent hampers the blabbering about quest solutions, which will inevitable occur):
1. Make the mobs respond differently at different stages of the quest, and make sure the players cannot take any shortcuts. (For instance, if you talk to MobA without first talking to MobB, you'll get a totally different response).
2. Add some random elements that send the players onto different paths. (You can use the player's class, race, level, and stats like intelligence, charisma, alignment etc. You can also make some mob or item that they need to find load in a number of different places.)
3. Make the rewards get increasingly smaller when you redo the quest, to discourage the "pharmers" that prefer repetitivy to exploring. (They should always get something, but eventually it will get to a point where it pays more to move on to another quest).

The more Quests I make, the more complex they tend to be. Lately I've got into twists that cater to the players who think and act differently than the mainstream.

The classical example is the "errand-boy" quest, where a mob sends you to deliver a letter or an item to another mob. You faithfully carry out the assignment, and get a new task, this time a bit more delicate. After repeating this a few times and gaining increasing trust from sender and receiver, you are finally sent with a letter that reveals a plan to overthrow the King. Now there are a number of persons in the kingdom apart from the intended receiver, (including the King himself), who'd be interested in that plan. Depending on who you actually give the letter to, several totally different scenarios will develop. Also, if you stray off the straight path, your original employer will sooner or later learn about your betrayal, and set out to get even.

Another example: You find a crumpled love letter in the drawer of a young man, who apparently never got along to sending it to his beloved. The normal action would be to bring it to the girl, and hope for a reward from her.
But what if the match is totally unsuitable and the families hate each other? What happens if you instead bring the letter to the girl's brother? Or the boy's father? Any of these actions will trigger a chain of totally different events.

Some players will never even realise that there are multiple opportunities in each of those quests. Others will gleefully explore all the possibilities, once they got a hang of the idea. It gives the same player the opportunity to do the same quest over and over, without actually repeating it, i.e. it becomes a bit more interesting.

To me this is an economical use of my time and ideas. It's also a lot more fun to design complex quests like that, than the usual simple ones.