Hi @jlat-newton,
Unfortunately there isn’t a straight forward answer to this one. The fastest (but not 100% accurate) way would be to filter by Next activity date. This includes logging a future call, sales email, or meeting using the Log feature, as well as creating a future task or scheduling a future meeting.
If the Next activity date is unknown, it means that the deal does not have a task. If a deal has a next activity date, it might not have a task but should have a call, sales email or meeting (in which case a task might not be needed?).
Alternatively, if you’re on a Professional license, you could create a cross-object report of all deals without tasks – let me know if you want to pursue this route and need more details. The data sources would be deals and sales activities, the approach to show all deals with an associated task without completion date. I’d choose a table visualization.
Best regards!