A subtask is a task within a task. Subtasks are part of the Dart hierarchy and are pieces of larger tasks broken down into more manageable parts.

Subtasks can be visible on the list, board, and roadmap layouts of your dartboard.

In a list or roadmap layout, you will be able to see a subtask icon on any parent task with the number of subtasks it has labeled:

By default, subtasks will be seen as indented under the parent task:

In a board layout, by default subtasks will also show as slightly indented under their parent task:

When you open a task with subtasks, you will see your subtasks (and their statuses) listed out.

When a task window is open, you can add a new subtask, update an existing subtask status, or open a subtask in order to add more information.

You can add tasks or subtasks from your dartboard without opening a task using the arrow icons or your tab key. To add a subtask to a task, click on the arrow beside the task title or select the task and press tab on your keyboard. From here, you will be able to enter a subtask title and then open the subtask to add in any further details:

When you have a task and would like to add subtasks, you can do so manually, or you can leverage Dart AI to help you write subtasks for the task.

First, ensure your task has at least a title that describes the task. Then, use the Task AI button at the top of your task window or the slash command in your task description to use AI to create subtasks. You will be able to edit these suggestions, delete them, or add other subtasks afterward as well:

You can replicate subtasks. You can also delete them. To do so, open the subtask. Then, choose the "more" icon at the top right of your subtask window and select "replicate" to make a copy" or "delete" to remove the subtask from the task:

You can size your tasks to understand how big or small they are in relation to other tasks in your project. By default, sizes add up inside of subtasks. For example, if you have 2 subtasks of a main task, one with a size of "1" and another with a size of "2" then the parent will by default show size "3." You can learn more about this rule and how to disable it in the article on sizes here.

By default parent tasks will take the last due date out of its subtasks. This has a variety of benefits, including that parents won't be due before their subtasks are. If you are using a full date range instead of just a due date, then parent tasks will take the latest end date of their subtasks. To learn more about due dates and this automation, including how to disable it, see the article on due dates.