Is there a word for:
'have to do first'
For example I can't do this task because I have a task that I have to do first. That task that I have to do first is a "_____ task".
The second task, which is blocked, is contingent or reliant upon the first. I don't want to call the first task independent or sovereign because the only reason I am doing the first task, is to get to the second. They are still linked, but have to be completed in a certain order.
I thought about using the term 'preceding' but I want to emphasise not just the positioning, but the fact that the first task actively blocks the second.