This page explains how the game stores quests. This is an advanced guide for mod developers.
All scripted quests are stored in an XNB file in the following directory Content\Data\Quests.xnb. If you want to add more quests, it is recommended that you make a new XNB package and use the content loader to load them into the game.
Each quest key must be unique positive integer. As of writing this, there doesn't appear to be any limitation on the size of the number (aside system architecture). It is recommended that you use something like the last 5 digits of your Nexus ID number as the first 5 digits and add quest IDs after that.
The values of the JSON elements follow a format much like that of the Modding:Dialogue#Format; using a forward slash delimited string to store its parameters. These parameters represent the following details about the quest.
|0||Type (e.g. Location, Basic, LostItem, etc)|
|2||Quest details/Flavour text|
|5||Next quest (-1 if N/A)|
|6||Gold (0 if none)|
|7||Reward description (Only if Gold is not -1)|
|9||(Optional) Reaction text|
"6": "ItemHarvest/Getting Started/If you want to become a farmer, you have to start with the basics. Use your hoe to till the soil, then use a seed packet on the tilled soil to sow a crop. Water every day until the crop is ready for harvest./Cultivate and harvest a parsnip./24/h7 8/100/-1/true"