Quests... oh the joy.... I rarely use quests in maps, but then again I never make single player maps where quests would be involved anyways.
Step 1: Initialize your quest(s)
Code:
Make your Quests
Events
Map initialization
Conditions
Actions
Quest - Create a Required, undiscovered quest titled First Quest with the description The Description, using icon path ReplaceableTextures\CommandButtons\BTNAmbush.blp
Quest - Create a quest requirement for (Last created quest) with the description Requirement for the...
Quest - Create a defeat condition with the description Defeat condition de...
Set quests[0] = (Last created quest)
-------- REPEAT FOR OTHER QUESTS --------
Now you should have ~3 triggers per quest that relate to that quest. These include:
Discovery (triggered by the discovery event, uses "Quest - Mark Quest as Discovered") (you may also want to flash the quest discovery icon at that point)
Completion (triggered by completion event, uses "Quest - Mark Quest as Completed")
Failure (only if the quest can be failed, usese "Quest - Mark Quest as Failed")
Also, if it is a required quest, the Failure trigger should include a line that defeats the player at that time.