Dependencies and subtasks

Under Linked work on the task detail, Add dependency and Add subtask connect tasks to each other. There are four kinds of link, and each one shows on both tasks — you add it from one side and the other side lists it too, under a heading naming its half of the relationship.

Blocked by

The strong link. Task A blocked by task B means A cannot proceed until B is finished. The board shows a red Blocked (n) chip on the card, and the task detail lists each blocker with its current status — so you can see at a glance whether the thing in your way is nearly done or has not started.

Cycles are rejected: the app refuses a dependency that would make two tasks block each other, directly or through a chain.

Relates to

The weak link — two tasks that inform each other but neither blocks the other. Shown as a blue Relates (n) chip.

Duplicates

For the same piece of work reported twice. The task you add it from lists it under Duplicates; the other one lists it under Duplicated by, and can only be removed from the side that created it.

Subtasks

A parent-child link for splitting a large piece of work. The child is a full task in its own right: it has its own key, sits in its own column, and can be assigned to someone else. The parent lists its Children; each child lists its Parent, and removes the link from the parent’s side.

A chain that would make a task its own ancestor is refused — That would make the task its own descendant — following the whole chain rather than only the immediate pair, the same way blocking cycles are.

A task has one parent. Giving a child to a second parent therefore takes it away from the first, in the same act — and that first parent is named nowhere in what you did. So it is told: the epic losing the child gets its own history row, removed ORB-14 from this task’s children, and its assignee and watchers are notified. Somebody re-organising their own epic cannot quietly empty yours.

What a link leaves behind

Every link added or removed is recorded on both tasks’ History, and notifies each one’s assignee and watchers — the same trio of history row, notification and webhook that a status change or a comment raises. Re-sending a link that is already there, or removing one this task does not hold, changes nothing and is recorded nowhere.

Tip

A practical rule: use blocked by when the order genuinely matters, relates to when you only want the reader to know the other task exists, and subtasks when one deliverable needs several people or several days.