Please don't make the quests simple and intuitive. In this type of game vague objectives force you to guess and explore there is a lot of synergy between the two that prevent either from becoming mundane and boring. Exploration and discovery are what keep the game exciting.
I would like to expand on this point. A quest is basically divided into three element - A back-story, a goal in the game world, a challenge in play. I think that this comment refers to the challenge in play. What makes a quest interesting is that it can be accomplished in an infinite number of ways and that not all of them are equally rewarding. In Terraria finding demonite was a side quest. While there was not backstory, and in the world of the game - all that you wanted is this demonite pickaxe and demonite armour, there were many ways to get the demonite. Initially you would have found it in small quantities underground, and later at the corpses of bosses, which you could defeat using various measures of balance between equipment and skill. Many good quests are of the form - assemble something (a vehicle, a structure etc') in a complex way which may result in different objects and then - test it against something and success to pass certain tests with it. Such are racing quests, tower defense quests, even boss quests are in a way of this sort. Another good alternative is nurture something - that is when there is some natural process (such as a plant growing or an eco-system) and you need to balance it and help to maintain its balance. Finally there are riddles with multiple solutions such as decreasing the temperature of a planet, terraforming it, generating electricity and so on. Good quests involve a lot of game mechanics and very little predecided scripts. Most importantly on the player side they should involve as little waiting\repetition as possible. ajilejy - I hope this is inline with what you had in mind. O.
Better yet, we have a variety. A few basic fetch quests never hurt anyone, and I'm sure a lot of people would want to see more complex and meaningful quests. That said, you don't want to make the objectives too vague. That can be frustrating, and might turn a lot of people off the quest.
It is certainly related. But specifically what I meant is don't give me a quest compass telling me exactly where to go, what to find, and what I need to do to get it. For example throwing the voodoo doll into the lava to summon the wall of flesh. The only piece of information given was to make a living sacrifice.
